Tootfinder

Quanutm-State Texture as a Resource: Measures and Nonclassical Interdependencies
Yuntao Cui, Zhaobing Fan, Sunho Kim
https://arxiv.org/abs/2508.07481 https://

Quanutm-State Texture as a Resource: Measures and Nonclassical Interdependencies
Quantum-state texture is a newly recognized quantum resource that has garnered attention with the advancement of quantum theory. In this work, we discuss several main tasks concerning quantum-state texture resource theory, including quantum-state texture measure, quantum state transformation under free operations, and relations between quantum resources. We first provide two new quantum-state texture measures and propose specific form of function for constructing quantum-state texture measures …

Nonequilibrium steady state in Lindblad dynamics for infinite quantum spin systems
Kenji Shimomura, Nagisa Hara, Seiichiro Kusuoka
https://arxiv.org/abs/2508.07448 https://

Nonequilibrium steady state in Lindblad dynamics for infinite quantum spin systems
We consider Lindblad dynamics of quantum spin systems on infinite lattices and define a nonequilibrium steady state (NESS) and a time-averaged nonequilibrium steady state (TANESS) on the basis of $C^*$-algebraic formalism. Generically, the NESS on an infinite system does not equal the thermodynamic limit of NESSs on finite systems. We give a sufficient condition that they coincide with each other, in terms of both a condition number, which quantifies the normality of a Liouvillian, and some spe…

Quantized Charge Accumulation in a Quantum Anomalous Hall System
Yuanze Li (State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, China), Jiahao Chen (State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, China), Renfei Wang (International Center for Quantum Materials, Peking University, Beijing, China), Yifan Zhang (School of Information Science and Technology, ShanghaiTech …

Quantized Charge Accumulation in a Quantum Anomalous Hall System
We report the first experimental observation of magnetic-field-induced quantized charge accumulation in a quantum anomalous Hall (QAH) system -- a phenomenon originating from the intrinsic two-dimensional surface state and fundamentally distinct from conventional edge-dependent transport phenomena. Our approach employs a novel out-of-plane capacitive detection method to directly probe this charge accumulation, revealing its distinction and correlation with other surface state properties, such a…

Power and limitations of distributed quantum state purification
Benchi Zhao, Yu-Ao Chen, Xuanqiang Zhao, Chengkai Zhu, Giulio Chiribella, Xin Wang
https://arxiv.org/abs/2509.08691

Power and limitations of distributed quantum state purification
Quantum state purification, which mitigates noise by exploiting multiple noisy copies of unknown states, has applications in quantum communication and computation with imperfect devices. Despite its importance, the fundamental capabilities and limitations of purification in distributed quantum systems remain largely unexplored. Here, we systematically study distributed quantum state purification under local operations and classical communication (LOCC). We prove that no nontrivial two-to-one LO…

A Novel Theoretical Approach on Micro-Nano Robotic Networks Based on Density Matrices and Swarm Quantum Mechanics
Maria Mannone, Mahathi Anand, Peppino Fazio, Abdalla Swikir
https://arxiv.org/abs/2509.08002

A Novel Theoretical Approach on Micro-Nano Robotic Networks Based on Density Matrices and Swarm Quantum Mechanics
In a robotic swarm, parameters such as position and proximity to the target can be described in terms of probability amplitudes. This idea led to recent studies on a quantum approach to the definition of the swarm, including a block-matrix representation. Here, we propose an advancement of the idea, defining a swarm as a mixed quantum state, to be described with a density matrix, whose size does not change with the number of robots. We end the article with some directions for future research.

Adaptive Quantum Computers: decoding and state preparation
Niels M. P. Neumann
https://arxiv.org/abs/2509.08718 https://arxiv.org/pdf/2509.08718

Adaptive Quantum Computers: decoding and state preparation
Interacting with a standard computer can enhance the capabilities of current quantum computers already today, particularly by offloading certain computations to the standard computer. Quantum computers that interact with standard computers to perform computations are called adaptive quantum computers. This work formalizes a model that describes these adaptive quantum computers. As quantum computers are still under development, this work focuses on computations that terminate after a fixed numbe…

Critical Majorana fermion at a topological quantum Hall bilayer transition
Cristian Voinea, Wei Zhu, Nicolas Regnault, Zlatko Papi\'c
https://arxiv.org/abs/2509.08036 https:…

Critical Majorana fermion at a topological quantum Hall bilayer transition
Quantum Hall bilayers are a uniquely tunable platform that can realize continuous transitions between distinct topological phases of matter. One prominent example is the transition between the Halperin state and the Moore--Read Pfaffian, long predicted to host a critical theory of Majorana fermions but so far not verified in unbiased microscopic simulations. Using the fuzzy sphere regularization, we identify the low-energy spectrum at this transition with the 3D gauged Majorana conformal field …

Laser-engineered $\Gamma$-point Topology in Trigonal Bismuthene
Zhe Li, Haijun Cao, Sheng Meng
https://arxiv.org/abs/2509.08068 https://arxiv.org/pdf/2509.…

Laser-engineered $Γ$-point Topology in Trigonal Bismuthene
The $Γ$-point topology represents a significant segment in the family of topological insulators. Here we provide a comprehensive prediction of light-induced $Γ$-point-based topological manipulation in trigonal bismuthene and its derivatives. Our findings unveil a two-stage process of topological phase transitions (TPT) as the laser intensity increases. Initially, a quantum-spin-Hall or metallic state transitions to a quantum-anomalous-Hall (QAH) state ($C$ = $\pm$3), followed by another TPT t…

Implementing a Universal Set of Geometric Quantum Gates through Dressed-State assisted STA
M. Estefan\'ia Rus, Alejandro Ferr\'on, Omar Osenda, Sergio S. Gomez
https://arxiv.org/abs/2509.08723 …

Implementing a Universal Set of Geometric Quantum Gates through Dressed-State assisted STA
Geometric quantum computation relies on the geometric phase that arises in adiabatic cyclic evolutions of non-degenerate quantum systems, enabling the design of robust quantum gates. However, the adiabatic condition requires long evolution times, making the system vulnerable to decoherence. In this work, we propose a scheme to realize fast and high-fidelity geometric quantum gates by applying the Superadiabatic Transitionless Driving (SATD) protocol within the dressed-state framework. We analyz…

Exact large deviations and emergent long-range correlations in sequential quantum East circuits
Jimin Li, Bruno Bertini, Juan P. Garrahan, Robert L. Jack
https://arxiv.org/abs/2509.07182

Exact large deviations and emergent long-range correlations in sequential quantum East circuits
Exploiting quantum measurements is a promising route for preparation of correlated quantum states. We use methods from large deviation theory to solve this problem exactly for a specific system: the deterministic quantum East circuit with boundary measurements. We show that conditioning on measurement outcomes generates a long-range correlated state, despite typical trajectories being trivial. We derive the channel that optimally realizes the rare measurement trajectories, and establish a forma…

Quantum Advantage from Sampling Shallow Circuits: Beyond Hardness of Marginals
Daniel Grier, Daniel M. Kane, Jackson Morris, Anthony Ostuni, Kewen Wu
https://arxiv.org/abs/2510.07808

Quantum Advantage from Sampling Shallow Circuits: Beyond Hardness of Marginals
We construct a family of distributions $\{\mathcal{D}_n\}_n$ with $\mathcal{D}_n$ over $\{0, 1\}^n$ and a family of depth-$7$ quantum circuits $\{C_n\}_n$ such that $\mathcal{D}_n$ is produced exactly by $C_n$ with the all zeros state as input, yet any constant-depth classical circuit with bounded fan-in gates evaluated on any binary product distribution has total variation distance $1 - e^{-Ω(n)}$ from $\mathcal{D}_n$. Moreover, the quantum circuits we construct are geometrically local and us…

Quantum Entanglement without Spin-Analyzing Power Dependence at the Colliders
Junle Pei, Tianjun Li, Lina Wu, Xiqing Hao, Xiaochuan Wang
https://arxiv.org/abs/2510.08031 https:/…

Quantum Entanglement without Spin-Analyzing Power Dependence at the Colliders
We study the quantum entanglement at the colliders which is independent of the spin-analyzing powers. Taking $Λ(\to pπ^-)\barΛ(\to \bar{p}π^+)$ as an example, we investigate whether quantum entanglement in fermion pairs produced at colliders can be certified by using only angular information from final-state decays, while remaining independent of the parity-violating decay parameters $α_Λ$ and $α_{\barΛ}$. Building on a general decomposition of any angular observable in terms of Wigner …

Voxel-scale quantum state control in nanorod ensembles using reconfigurable needle beams
G. A. Mantashian, D. B. Hayrapetyan, P. A. Mantashyan
https://arxiv.org/abs/2510.07767 h…

Voxel-scale quantum state control in nanorod ensembles using reconfigurable needle beams
Precisely addressing single nanostructures inside dense ensembles remains a bottleneck for scalable photonic and quantum information devices. Here we demonstrate, through comprehensive finite element and variational Monte-Carlo modelling, that a reconfigurable three-dimensional array of needle shaped beams can selectively switch the quantum optical response of individual InAs nanorods embedded in GaAs. By tuning the local non resonant intensity pattern the exciton and biexciton energies were ca…

The thermodynamics of readout devices and semiclassical gravity
Samuel Fedida, Adrian Kent
https://arxiv.org/abs/2509.07096 https://arxiv.org/pdf/2509.0709…

The thermodynamics of readout devices and semiclassical gravity
We analyse the common claim that nonlinear modifications of quantum theory necessarily violate the second law of thermodynamics. We focus on hypothetical extensions of quantum theory that contain readout devices. These black boxes provide a classical description of quantum states without perturbing them. They allow quantum state cloning, though in a way consistent with the relativistic no-signalling principle. We review the existence of such devices in the context of Moller-Rosenfeld semiclassi…

Proton-proton scattering on a quantum computer
Ratna Khadka, Gautam Rupak
https://arxiv.org/abs/2508.07986 https://arxiv.org/pdf/2508.07986

Proton-proton scattering on a quantum computer
Scattering of charged particles is ubiquitous in nuclear physics. We calculate the proton-proton $s$-wave phase shift at low energy relevant to solar physics. The phase shift is calculated from the ratio of the regular and irregular solutions to the radial Schrödinger equation on a hard spherical wall boundary for the ground state. The ground state energy is calculated using a hybrid quantum-classical variational algorithm. A theory with short-ranged nuclear interaction in the presence of the …

Rigged Hilbert Space Formulation of Quantum Thermo Field Dynamics and Mapping to Rigged Liouville Space
Junichi Takahashi, Shousuke Ohmori
https://arxiv.org/abs/2508.06923 https…

Rigged Hilbert Space Formulation of Quantum Thermo Field Dynamics and Mapping to Rigged Liouville Space
The rigged Hilbert space, a triplet extension of the Hilbert space, provides a mathematically rigorous foundation for quantum mechanics by extending the Hilbert space to accommodate generalized eigenstates. In this paper, we construct a triplet structure for the thermal space arising in Thermo Field Dynamics with the aid of the tensor product formulation of rigged Hilbert spaces, a formalism that reformulates thermal averages as pure-state expectation values in a doubled Hilbert space. We then …

Robust Belief-State Policy Learning for Quantum Network Routing Under Decoherence and Time-Varying Conditions
Amirhossein Taherpour, Abbas Taherpour, Tamer Khattab
https://arxiv.org/abs/2509.08654

Robust Belief-State Policy Learning for Quantum Network Routing Under Decoherence and Time-Varying Conditions
This paper presents a feature-based Partially Observable Markov Decision Process (POMDP) framework for quantum network routing, combining belief-state planning with Graph Neural Networks (GNNs) to address partial observability, decoherence, and scalability challenges in dynamic quantum systems. Our approach encodes complex quantum network dynamics, including entanglement degradation and time-varying channel noise, into a low-dimensional feature space, enabling efficient belief updates and scala…

Quantum Mpemba-like effect in Unruh thermalization
Zihao Wang, Wenjing Chen, Si-Wei Han, Xiaoshan Feng, Linmu Qiao, Zhichun Ouyang, Jun Feng
https://arxiv.org/abs/2509.05756 htt…

Quantum Mpemba-like effect in Unruh thermalization
We revisit the thermal nature of the Unruh effect within a quantum thermodynamic framework. For a Unruh-deWitt (UDW) detector in $n$-dimensional Minkowski spacetime, we demonstrate that its irreversible thermalization to a Gibbs equilibrium state follows distinct trajectories on the Bloch sphere, which depend on the types of fields the detector interacts with, as well as the spacetime dimensionality. Using thermodynamic process functions, particularly quantum coherence and heat that form the qu…

Readout of multi-level quantum geometry from electronic transport
Raffael L. Klees, M\'onica Benito
https://arxiv.org/abs/2508.08239 https://arxiv.org/…

Readout of multi-level quantum geometry from electronic transport
The quantum geometric tensor (QGT) of a quantum system in a given parameter space captures both the geometry of the state manifold and the topology of the system. While the local QGT elements have been successfully measured in various platforms, the challenge of detecting them in electronic transport systems - such as tunnel or molecular junctions - has yet to be resolved. To fill this gap, we propose a measurement protocol based on weak and resonant parameter modulations, and theoretically dem…

QCardEst/QCardCorr: Quantum Cardinality Estimation and Correction
Tobias Winker, Jinghua Groppe, Sven Groppe
https://arxiv.org/abs/2509.08817 https://arxiv…

QCardEst/QCardCorr: Quantum Cardinality Estimation and Correction
Cardinality estimation is an important part of query optimization in DBMS. We develop a Quantum Cardinality Estimation (QCardEst) approach using Quantum Machine Learning with a Hybrid Quantum-Classical Network. We define a compact encoding for turning SQL queries into a quantum state, which requires only qubits equal to the number of tables in the query. This allows the processing of a complete query with a single variational quantum circuit (VQC) on current hardware. In addition, we compare mu…

Intermediate Silicon Tracker in sPHENIX at RHIC
Cheng-Wei Shih
https://arxiv.org/abs/2508.06536 https://arxiv.org/pdf/2508.06536

Intermediate Silicon Tracker in sPHENIX at RHIC
The sPHENIX collaboration has been taking data since 2023 at the Relativistic Heavy Ion Collider in BNL to study the Quark-Gluon Plasma and cold Quantum Chromodynamics (QCD). The tracking system of sPHENIX consists of a time projection chamber, a MAPS-based vertex detector, and an intermediate silicon tracker (INTT). Together with the sPHENIX full barrel calorimeter system, the measurement of the heavy-flavor jets and the upsilon-state identification are enabled. INTT, surrounding the collision…

From Physical to Logical: Graph-State-Based Connectivity in Quantum Networks
Mateo M. Blanco, Manuel Fern\'andez-Veiga, Ana Fern\'andez-Vilas, Rebeca P. D\'iaz-Redondo
https://arxiv.org/abs/2509.08384

From Physical to Logical: Graph-State-Based Connectivity in Quantum Networks
Entanglement is a key resource in quantum communication, but bipartite schemes are often insufficient for advanced protocols like quantum secret sharing or distributed computing. Graph states offer a flexible way to represent and manage multipartite entanglement in quantum networks, enabling logical connectivity through local operations and classical communication (LOCC). In this work, we extend existing approaches based on bi-star configurations to more complex multi-star topologies. We analyz…

Field-Tailoring Quantum Materials: Magneto-Synthesis of Metastable Metallic States in a Spin-Orbit-Coupled Trimer Iridate
Tristan R. Cao, Hengdi Zhao, Xudong Huai, Arabella Quane, Varun Narayanan, Thao T. Tran, Feng Ye, Gang Cao
https://arxiv.org/abs/2508.07545

Field-Tailoring Quantum Materials: Magneto-Synthesis of Metastable Metallic States in a Spin-Orbit-Coupled Trimer Iridate
We demonstrate that modest magnetic fields (a fraction of a Tesls), when applied during high-temperature crystal growth, can profoundly alter the structural and electronic ground state of a spin-orbit-coupled, antiferromagnetic trimer lattice. Using an iridate as a model system, we show that magneto-synthesis, a field-assisted synthesis approach, stabilizes a structurally compressed, metastable metallic phase that cannot be accessed through conventional synthesis routes. This field-tailored pha…

Expanding a 4-qubit Dicke State a to 5-qubit Dicke State with Limited Qubit Access
Bibhuti Thapa, Oberon Moran, Duc-Kha Vu, Fatih Ozaydin
https://arxiv.org/abs/2508.07977 https:…

Expanding a 4-qubit Dicke State a to 5-qubit Dicke State with Limited Qubit Access
In scenarios where full access to all qubits of a multipartite quantum system is available and global operations can be implemented, the preparation of arbitrary entangled states - including multipartite Dicke states - is theoretically straightforward. However, practical constraints often limit direct control over all qubits. In this work, we first present an efficient method for preparing a four-qubit Dicke state, and then demonstrate how a four-qubit Dicke state can be expanded to a five-qubi…

Multi-laser stabilization with an atomic-disciplined photonic integrated resonator
Andrei Isichenko, Andrew S. Hunter, Nitesh Chauhan, John R. Dickson, T. Nathan Nunley, Josiah R. Bingaman, David A. S. Heim, Mark W. Harrington, Kaikai Liu, Paul D. Kunz, Daniel J. Blumenthal
https://arxiv.org/abs/2509.09124

Multi-laser stabilization with an atomic-disciplined photonic integrated resonator
Precision atomic and quantum experiments rely on ultra-stable narrow linewidth lasers constructed using table-top ultra-low expansion reference cavities. These experiments often require multiple lasers, operating at different wavelengths, to perform key steps used in state preparation and measurement required in quantum sensing and computing. This is traditionally achieved by disciplining a cavity-stabilized laser to a key atomic transition and then transferring the transition linewidth and sta…

Quantum MIMO Diversity over Discrete-Variable Crosstalk Channels
Shehbaz Tariq, Junaid ur Rehman, Symeon Chatzinotas
https://arxiv.org/abs/2508.07344 https://

Quantum MIMO Diversity over Discrete-Variable Crosstalk Channels
Quantum communication plays a pivotal role in enabling distributed quantum computing and sensing. Diversity strategies can be used to increase the communication reliability (in the sense of output fidelity with respect to the input quantum state) when multiple communication channels are available. The current paper proposes a diversity strategy for quantum discrete variable (DV) multiple-input-multiple-output (MIMO) channels, utilizing approximate cloning to distribute information across multip…

Bilateral Hydrogenation Realizes High-Temperature Quantum Anomalous Hall Insulator in 2D Cr$_{\text{2}}$Ge$_{\text{2}}$Te$_{\text{6}}$
Xiang Li, Xin-Wei Yi, Jing-Yang You, Jia-Wen Li, Qing-Han Yang, Gang Su, Bo Gu
https://arxiv.org/abs/2509.09164

Bilateral Hydrogenation Realizes High-Temperature Quantum Anomalous Hall Insulator in 2D Cr$_{\text{2}}$Ge$_{\text{2}}$Te$_{\text{6}}$
The pursuit of high-temperature quantum anomalous Hall (QAH) insulators faces fundamental challenges, including narrow topological gaps and low Curie temperatures ($T_{\text{C}}$) in existing materials. Here, we propose a transformative strategy using bilateral hydrogenation to engineer a robust QAH state in the topologically trivial ferromagnetic semiconductor Cr$_{\text{2}}$Ge$_{\text{2}}$Te$_{\text{6}}$. First-principles calculations reveal that hydrogenation induces a topological phase tran…

A Method for Constructing Quasi-Random Peaked Quantum Circuits
O. G. Udalov
https://arxiv.org/abs/2508.07491 https://arxiv.org/pdf/2508.07491

A Method for Constructing Quasi-Random Peaked Quantum Circuits
An algorithm is proposed for constructing quasi-random "peaked" quantum circuits, i.e., circuits whose final qubit state exhibits a high probability concentration on a specific computational basis state. These circuits consist of random gates arranged in a brick-wall architecture. While the multiqubit state in the middle of the circuit can exhibit significant entanglement, the final state is, with high probability, a predetermined pure bitstring. A technique is introduced to obscure the final b…

Fast and efficient long-distance quantum state transfer in long-range spin-$\frac{1}{2}$ models
F. Faria, C. C. Nelmes, T. J. G. Apollaro, T. P. Spiller, I. D'Amico
https://arxiv.org/abs/2508.08182

Fast and efficient long-distance quantum state transfer in long-range spin-$\frac{1}{2}$ models
Quantum state transfer is investigated beyond the nearest-neighbour coupling scheme in long spin-$\frac{1}{2}$ linear chains. Exploiting the properties of the next-nearest neighbour Hamiltonian's dispersion relation, it is shown that with minimal engineering, i.e., an on-site magnetic field on the two end sites and only a few symmetrically-modified end inter-site couplings, an average transfer fidelity above $99\%$ can be achieved. To leading order, the required time scales linearly with the le…

Uncovering domain morphology in an unconventional magnet with scanning diamond quantum magnetometry
Freya Johnson (Cavendish Laboratory, University of Cambridge), Jan Zemen (Faculty of Electrical Engineering, Czech Technical University in Prague), Helena Knowles (Cavendish Laboratory, University of Cambridge), Lesley F. Cohen (Department of Physics, Blackett Laboratory, Imperial College London)

Uncovering domain morphology in an unconventional magnet with scanning diamond quantum magnetometry
Unconventional magnetic materials including non-collinear antiferromagnets, p-wave magnets and altermagnets, are an emerging frontier for quantum spintronics and hybrid quantum devices. Critical to the application of these materials is control over the magnetic domain state, as their unique, symmetry-driven properties vanish in a multi-domain limit. However, the mechanisms governing domain formation in materials with compensated local moments remain poorly understood. In this work, we examine t…

Steady state properties of periodically driven quantum systems
Milan \v{S}indelka, David Gelbwaser-Klimovsky
https://arxiv.org/abs/2508.07674 https://arxiv…

Steady state properties of periodically driven quantum systems
Periodic driving is used to steer physical systems to unique stationary states or nonequilibrium steady states (NESS), producing enhanced properties inaccessible to non-driven systems. For open quantum systems, characterizing the NESS is challenging and existing results are generally limited to specific types of driving and the Born-Markov approximation. Here we go beyond these limits by studying a generic periodically driven $ N$-level quantum system interacting with a low-density thermal gas.…

A penalty-free quantum algorithm to find energy eigenstates
Nannan Ma, Heng Dai, Jiangbin Gong
https://arxiv.org/abs/2509.09148 https://arxiv.org/pdf/2509.…

A penalty-free quantum algorithm to find energy eigenstates
Finding eigenstates of a given many-body Hamiltonian is a long-standing challenge due to the perceived computational complexity. Leveraging on the hardware of a quantum computer accommodating the exponential growth of the Hilbert space size with the number of qubits, more quantum algorithms to find the eigenstates of many-body Hamiltonians will be of wide interest with profound implications and applications. In this work, we advocate a quantum algorithm to find the ground state and excited stat…

Three-Dimensional Electrostatic and Quantum-Confinement Modeling of Silicon Nanowire Double Quantum Dots
Nilesh Pandey, Dipanjan Basu, Leonard F Register, Sanjay K Banerjee
https://arxiv.org/abs/2510.07831

Three-Dimensional Electrostatic and Quantum-Confinement Modeling of Silicon Nanowire Double Quantum Dots
We present a three-dimensional simulation study of silicon nanowire double quantum dots with leads, which extends beyond traditional effective-mass or quasi-1D and quasi-2D approaches typically applied to bulk or planar geometries. Using the Sentaurus QTX, we self-consistently couple a 3-D Poisson solver with two-dimensional Schrödinger solutions along the strongly confined width * thickness cross-sections normal to the transport direction, yielding bound-state energies and wavefunctions acros…

Special Issue: Commemorating the 110th Anniversary of TANG Au-chin's Birthday Calculation of the Green's function on near-term quantum computers via Cartan decomposition
Lingyun Wan, Jie Liu, Jinlong Yang
https://arxiv.org/abs/2509.09248

Special Issue: Commemorating the 110th Anniversary of TANG Au-chin's Birthday Calculation of the Green's function on near-term quantum computers via Cartan decomposition
Accurate computation of the Green's function is crucial for connecting experimental observations to the underlying quantum states. A major challenge in evaluating the Green's function in the time domain lies in the efficient simulation of quantum state evolution under a given Hamiltonian-a task that becomes exponentially complex for strongly correlated systems on classical computers. Quantum computing provides a promising pathway to overcome this barrier by enabling efficient simulation of quan…

A scalable method for cavity-enhanced solid-state quantum sensors
Daniel J. Tibben, Roy Styles, David A. Broadway, Jean-Philippe Tetienne, Daniel E. G\'omez, Philipp Reineck
https://arxiv.org/abs/2509.04760

A scalable method for cavity-enhanced solid-state quantum sensors
Photoluminescent color centers in diamond and hexagonal boron nitride (hBN) are powerful nanoscale solid-state quantum sensors that are explored in a plethora of quantum technologies. Methods for integrating them into macroscopic structures that improve their sensitivity and enable their large-scale deployment are highly sought after. Here, we demonstrate cavity-enhanced photoluminescence (PL) of fluorescent nanodiamonds (FNDs) and hBN nanoparticles (NPs) embedded in polymer-based thin-film opt…

Optimal detection of quantum states via projective measurements
Giuseppe Del Vecchio Del Vecchio, Satya N. Majumdar
https://arxiv.org/abs/2509.08556 https://

Optimal detection of quantum states via projective measurements
We consider the quantum dynamical evolution of a fully-connected quantum system subjected to random projective measurements and study the first detection time of an extended subspace of the Hilbert space. Exact analytical expressions are obtained for the mean first detection time and the full first detection probability distribution as functionals of the initial state $\ket{ψ_0}$ and the measurement rate $r$. Exact enumeration agrees perfectly with our analytical predictions.

Loss-tolerant parallelized Bell-state generation with a hybrid cat qudit
Z. M. McIntyre, W. A. Coish
https://arxiv.org/abs/2509.08577 https://arxiv.org/pdf…

Loss-tolerant parallelized Bell-state generation with a hybrid cat qudit
Having multiple Bell pairs shared by distant quantum registers provides a key resource for both quantum networks and distributed quantum computing. In this paper, we present a protocol for parallelized Bell-pair generation that uses the phase of a coherent light pulse to encode a qudit, enabling the simultaneous generation of multiple Bell pairs. By encoding a qudit in a basis of light-matter Schrödinger's cat states, the loss of a photon in transit can be detected through an $XX$ parity syndr…

Average Contraction Coefficients of Quantum Channels
Ruben Ibarrondo, Daniel Stilck Fran\c{c}a
https://arxiv.org/abs/2508.08214 https://arxiv.org/pdf/2508.…

Average Contraction Coefficients of Quantum Channels
The data-processing inequality ensures quantum channels reduce state distinguishability, with contraction coefficients quantifying optimal bounds. However, these can be overly optimistic and not representative of the usual behavior. We study how noise contracts distinguishability of `typical' states, beyond the worst-case. To that end, we introduce and study a family of moments of contraction for quantum divergences, which interpolate between the worst-case contraction coefficient of a channel …

Reducing quantum resources for observable estimation with window-assisted coherent QPE
Harriet Apel, Cristian L. Cortes, Jessica Lemieux, Mark Steudtner
https://arxiv.org/abs/2508.06677

Reducing quantum resources for observable estimation with window-assisted coherent QPE
Quantum Phase Estimation (QPE) routines are known to fail probabilistically even with perfect gates and input states. This effect stems from an incompatibility of finite-sized quantum registers to capture a phase within QPE with phase angles of infinite precision, and the effect extend even beyond what would be reasonably expected from rounding. This effect can be partially mitigated by biasing the phase register with a window, or taper state, from classical signal processing. This paper focuse…

Quantum sensing with a spin ensemble in a two-dimensional material
Souvik Biswas, Giovanni Scuri, Noah Huffman, Eric I. Rosenthal, Ruotian Gong, Thomas Poirier, Xingyu Gao, Sumukh Vaidya, Abigail J. Stein, Tsachy Weissman, James H. Edgar, Tongcang Li, Chong Zu, Jelena Vu\v{c}kovi\'c, Joonhee Choi
https://arxiv.org/abs/2509.08984…

Quantum sensing with a spin ensemble in a two-dimensional material
Quantum sensing with solid-state spin defects has transformed nanoscale metrology, offering sub-wavelength spatial resolution with exceptional sensitivity to multiple signal types. Maximizing these advantages requires minimizing both the sensor-target separation and detectable signalthreshold. However, leading platforms such as nitrogen-vacancy (NV) centers in diamond suffer performance degradation near surfaces or in nanoscale volumes, motivating the search for optically addressable spin senso…

Acousto-optical Floquet engineering of a single-photon emitter
Daniel Groll, Daniel Wigger, Matthias Wei{\ss}, Mingyun Yuan, Alexander Kuznetsov, Alberto Hern\'andez-M\'inguez, Hubert J. Krenner, Tilmann Kuhn, Pawe{\l} Machnikowski
https://arxiv.org/abs/2509.09559

Acousto-optical Floquet engineering of a single-photon emitter
The combination of solid state single-photon emitters and mechanical excitations into hybrid infrastructures is a promising approach for new developments in quantum technology. Here we investigate theoretically the resonance fluorescence (RF) spectrum of an acoustically modulated single-photon emitter under arbitrarily strong optical driving. In the spectrum, the combination of Mollow triplet physics and phonon sidebands results in a complex structure of crossings, anti-crossings, and line supp…

Extracting and charging energy into almost unknown quantum states
Andrea Canzio, Vasco Cavina, Roberto Menta, Vittorio Giovannetti
https://arxiv.org/abs/2509.08899 https://

Extracting and charging energy into almost unknown quantum states
In this work, we investigate the amount of energy that can be extracted or charged through unitary operations when only minimal information about the state is known. Assuming knowledge of only the mean energy of the state, we start by developing optimal upper bounds for the work that can be unitarily extracted or charged in this scenario. In deriving these upper bounds, we provide a complete characterization of the minimum ergotropy and anti-ergotropy for density matrices with fixed average ene…

Benchmarking Optimization Algorithms for Automated Calibration of Quantum Devices
Kevin Pack, Shai Machnes, Frank K. Wilhelm
https://arxiv.org/abs/2509.08555 https://

Benchmarking Optimization Algorithms for Automated Calibration of Quantum Devices
We present the results of a comprehensive study of optimization algorithms for the calibration of quantum devices. As part of our ongoing efforts to automate bring-up, tune-up, and system identification procedures, we investigate a broad range of optimizers within a simulated environment designed to closely mimic the challenges of real-world experimental conditions. Our benchmark includes widely used algorithms such as Nelder-Mead and the state-of-the-art Covariance Matrix Adaptation Evolution …

Frequency drift corrected ultra-stable laser through phase-coherent fiber producing a quantum channel
Stanley Johnson, Sandeep Mishra, Anirban Pathak, Subhadeep De
https://arxiv.org/abs/2509.08419

Frequency drift corrected ultra-stable laser through phase-coherent fiber producing a quantum channel
Phase coherent fibers (PCF) are essential to distribute nearly monochromatic photons, ultra-stable in their frequency and phases, which have demanding requirements for state-of-the-art networked experiments, quantum as well as very high-speed communications. We report the development of a novel system that produces PCF links, also actively corrects the unavoidable slow frequency drift of the source laser. The PCF follows white phase noise limited $σ_o \times τ^{-1}$ stability behavior having …

Fractional quantum Hall state at $\nu = 1/2$ with energy gap up to 6 K, and possible transition from one- to two-component state
Siddharth Kumar Singh, Chengyu Wang, Adbhut Gupta, Kirk W. Baldwin, Loren N. Pfeiffer, Mansour Shayegan
https://arxiv.org/abs/2510.03983

Fractional quantum Hall state at $ν= 1/2$ with energy gap up to 6 K, and possible transition from one- to two-component state
The fractional quantum Hall state (FQHS) observed in the lowest Landau level at filling factor $ν=1/2$ in wide quantum wells has been enigmatic for decades because the two-dimensional electron system (2DES) has a bilayer charge distribution but with significant interlayer tunneling. Of particular interest is whether the 1/2 FQHS in this system has a one-component (1C) or two-component (2C) origin; these are typically identified as the Pfaffian (non-Abelian) or the $Ψ_{331}$ (Abelian) FQHSs, r…

Exponential Lindbladian fast forwarding and exponential amplification of certain Gibbs state properties
Zhong-Xia Shang, Dong An, Changpeng Shao
https://arxiv.org/abs/2509.09517

Exponential Lindbladian fast forwarding and exponential amplification of certain Gibbs state properties
We investigate Lindbladian fast-forwarding and its applications to estimating Gibbs state properties. Fast-forwarding refers to the ability to simulate a system of time $t$ using significantly fewer than $t$ queries or circuit depth. While various Hamiltonian systems are known to circumvent the no fast-forwarding theorem, analogous results for dissipative dynamics, governed by Lindbladians, remain largely unexplored. We first present a quantum algorithm for simulating purely dissipative Lindbla…

Quantum-Kaniadakis entropy as a measure of quantum correlations through implicit bounds
Narayan S Iyer, Shraddha Sharma
https://arxiv.org/abs/2510.07241 https://

Quantum-Kaniadakis entropy as a measure of quantum correlations through implicit bounds
In the present article, we examine the relationship of negative conditional quantum Kaniadakis entropy ($α-$CQKE) with the fully entangled fraction (FEF) which is a substantial yardstick for quantum information processing protocols including teleportation, and quantum steerability, executed over four vital quantum states with maximally mixed marginals, the 2-qubit Werner state, the 2-qubit Weyl state, the 2-qudit Werner state and the isotropic state. We initiate our analysis in 2$\otimes$2 sys…

Rotation Errors Due to Field Quantization for Simultaneously Driven Atoms
Hunter Lindemann, Shanon Vuglar, Julio Gea-Banacloche
https://arxiv.org/abs/2508.06769 https://

Rotation Errors Due to Field Quantization for Simultaneously Driven Atoms
When an electromagnetic field in a coherent or quasiclassical (e.g., squeezed) state is used to simultaneously drive an ensemble of two-level atoms, the quantum nature of the field will, in general, cause the final state of the atoms to differ from the one predicted for a totally classical field. This is a potential source of error in quantum logic gates in which the gate is the rotation of the atoms by a laser. In this paper, we use second order perturbation theory to find how this error scale…

Speeding up Pontus-Mpemba effects via dynamical phase transitions
Andrea Nava, Reinhold Egger, Bidyut Dey, Domenico Giuliano
https://arxiv.org/abs/2509.09366 https://

Speeding up Pontus-Mpemba effects via dynamical phase transitions
We demonstrate that open quantum systems exhibiting dynamical phase transitions (DPTs) allow for highly efficient protocols implementing the Pontus-Mpemba effect. The relaxation speed-up toward a predesignated target state is tied to the existence of a long metastable time window preceding the DPT and can be exploited in applications to systematically optimize quantum protocols. As paradigmatic example for the connection between DPTs and quantum Mpemba effects, we study one-dimensional (1D) int…

Optimality of universal conclusive entanglement purification protocols
Alexandre C. Orthey, Aby Philip, Tulja Varun Kondra, Alexander Streltsov
https://arxiv.org/abs/2509.09423 …

Optimality of universal conclusive entanglement purification protocols
Entanglement purification is essential for quantum technologies; yet, rigorous bounds on the success probability for universal protocols -- those requiring no prior knowledge about the input state -- have remained underexplored. We establish such fundamental limits for conclusive protocols distilling perfect Bell states from a pure two-qubit states by deriving the optimal success probability starting with: two copies of a state with known Schmidt basis, and four copies of a state with unknown S…

Quantum Walks for Chemical Reaction Networks
Seenivasan Hariharan, Sebastian Zur, Sachin Kinge, Lucas Visscher, Kareljan Schoutens, Stacey Jeffery
https://arxiv.org/abs/2509.07890

Quantum Walks for Chemical Reaction Networks
We lay the foundation for a quantum algorithmic framework to analyse fixed-structure chemical reaction networks (CRNs) using quantum random walks (QRWs) via electrical circuit theory. We model perturbations to CRNs, such as, species injections that shift steady-state concentrations, while keeping the underlying species-reaction graph fixed. Under physically meaningful mass-action constraints, we develop quantum algorithms that (i) decide reachability of target species after perturbation, (ii) s…

Ergotropic advantage in a measurement-fueled quantum heat engine
Sidhant Jakhar, Ramandeep S. Johal
https://arxiv.org/abs/2509.09402 https://arxiv.org/pdf/…

Ergotropic advantage in a measurement-fueled quantum heat engine
This paper investigates a coupled two-qubits heat engine fueled by generalized measurements of the spin components and using a single heat reservoir as sink. Our model extends the four-stroke engine proposed by Yi and coworkers [Phys. Rev. E {\bf 96}, 022108 (2017)] by introducing an ergotropy-extracting stroke, resulting in a five-stroke cycle. For measurements along z-z directions, we find two possible occupation distributions that yield an active state and the ergotropic stroke improves the …

Process Tensor Approaches to Non-Markovian Quantum Dynamics
Jonathan Keeling, E. Miles Stoudenmire, Mari-Carmen Ba\~nuls, David R. Reichman
https://arxiv.org/abs/2509.07661 http…

Process Tensor Approaches to Non-Markovian Quantum Dynamics
The paradigm of considering open quantum systems -- i.e. focusing only on the system of interest, and treating the rest of the world as an effective environment -- has proven to be a highly effective way to understand a range of quantum systems, across areas of study such as quantum optics, cold atoms, superconducting qubits, and impurities in solid-state systems. A common approach in many of these contexts has been to consider simplified approaches based on the Born and Markov approximations. …

Hardness of recognizing phases of matter
Thomas Schuster, Dominik Kufel, Norman Y. Yao, Hsin-Yuan Huang
https://arxiv.org/abs/2510.08503 https://arxiv.org/…

Hardness of recognizing phases of matter
We prove that recognizing the phase of matter of an unknown quantum state is quantum computationally hard. More specifically, we show that the quantum computational time of any phase recognition algorithm must grow exponentially in the range of correlations $ξ$ of the unknown state. This exponential growth renders the problem practically infeasible for even moderate correlation ranges, and leads to super-polynomial quantum computational time in the system size $n$ whenever $ξ= ω(\log n)$. Ou…

Randomized truncation of quantum states
Aram W. Harrow, Angus Lowe, Freek Witteveen
https://arxiv.org/abs/2510.08518 https://arxiv.org/pdf/2510.08518

Randomized truncation of quantum states
A fundamental task in quantum information is to approximate a pure quantum state in terms of sparse states or, for a bipartite system, states of bounded Schmidt rank. The optimal deterministic approximation in each case is straightforward, and maximizes the fidelity: keep the largest entries or singular values. On the other hand, random mixtures of sparse states can achieve quadratically improved trace distances, and yield nontrivial bounds on other distance measures like the robustness. In thi…

Behind the scenes of the Quantum Extreme Learning Machines
A. De Lorenzis, M. P. Casado, N. Lo Gullo, T. Lux, F. Plastina, A. Riera
https://arxiv.org/abs/2509.06873 https://

Behind the scenes of the Quantum Extreme Learning Machines
In recent years, Quantum Machine Learning (QML) has grown rapidly, emerging as a promising approach to make quantum computing implementation competitive. In this work, we investigate Quantum Extreme Learning Machines (QELM), a quantum variant of Extreme Learning Machines where training is restricted to the output layer. The proposed architecture combines dimensionality reduction (via PCA or Autoencoders), quantum state encoding, evolution under an XX Hamiltonian, and measurement, providing feat…

A Structural Theory of Quantum Metastability: Markov Properties and Area Laws
Thiago Bergamaschi, Chi-Fang Chen, Umesh Vazirani
https://arxiv.org/abs/2510.08538 https://

A Structural Theory of Quantum Metastability: Markov Properties and Area Laws
Statistical mechanics assumes that a quantum many-body system at low temperature can be effectively described by its Gibbs state. However, many complex quantum systems exist only as metastable states of dissipative open system dynamics, which appear stable and robust yet deviate substantially from true thermal equilibrium. In this work, we model metastable states as approximate stationary states of a quasi-local, (KMS)-detailed-balanced master equation representing Markovian system-bath interac…

A general dark-state theory for arbitrary multilevel quantum systems
Xuan Zhao, Le-Man Kuang, Jie-Qiao Liao
https://arxiv.org/abs/2510.05561 https://arxiv.…

A general dark-state theory for arbitrary multilevel quantum systems
The dark-state effect, caused by destructive quantum interference, is an important physical effect in atomic physics and quantum optics. It not only deepens the understanding of light-atom interactions, but also has wide application in quantum physics and quantum information. Therefore, how to efficiently and conveniently determine the number and form of the dark states in multilevel quantum systems with complex transitions is an important and interesting topic in this field. In this work, we p…

Guess your neighbor's input: Quantum advantage in Feige's game
Simon Schmidt, Sigurd A. L. Storgaard, Michael Walter, Yuming Zhao
https://arxiv.org/abs/2510.08484 https:…

Guess your neighbor's input: Quantum advantage in Feige's game
In this article, we study a nonlocal game with two questions and three answers per player, which was first considered by Feige in 1991, and show that there is quantum advantage in this game. We prove that the game is a robust self-test for the $3$-dimensional maximally entangled state. Furthermore, we show that the game can be seen as the "or" of two games that each do not have quantum advantage. Lastly, we investigate the behavior of the game with respect to parallel repetition in the classica…

Software Framework for Optically Accessible Quantum Memory Using Group-IV Color Centers in Diamond
Yannick Strocka, Mohamed Belhassen, Tim Schr\"oder, Gregor Pieplow
https://arxiv.org/abs/2510.07045

Software Framework for Optically Accessible Quantum Memory Using Group-IV Color Centers in Diamond
In the rapidly evolving field of quantum technology, the precise and detailed description of quantum components is not just a necessity but the foundation for advancing research, development, and applications. Optically accessible quantum memories are key building blocks for devices such as quantum repeaters and two-factor authentication. The memory we describe here is based on a tin-vacancy color center coupled to a highly efficient cavity. It leverages state-dependent reflection from the cavi…

On the convergence of the variational quantum eigensolver and quantum optimal control
Marco Wiedmann, Daniel Burgarth, Gunther Dirr, Thomas Schulte-Herbr\"uggen, Emanuel Malvetti, Christian Arenz
https://arxiv.org/abs/2509.05295

On the convergence of the variational quantum eigensolver and quantum optimal control
When does a variational quantum algorithm converge to a globally optimal problem solution? Despite the large literature around variational approaches to quantum computing, the answer is largely unknown. We address this open question by developing a convergence theory for the variational quantum eigensolver (VQE). By leveraging the terminology of quantum control landscapes, we prove a sufficient criterion that characterizes when convergence to a ground state of a Hamiltonian can be guaranteed fo…

Approximating quantum states by states of low rank
Nathaniel Johnston, Chi-Kwong Li
https://arxiv.org/abs/2510.08463 https://arxiv.org/pdf/2510.08463

Approximating quantum states by states of low rank
Given a positive integer k, it is natural to ask for a formula for the distance between a given density matrix (i.e., mixed quantum state) and the set of density matrices of rank at most k. This problem has already been solved when "distance" is measured in the trace or Frobenius norm. We solve it for all other unitary similarity invariant norms. We also present some consequences of our formula. For example, in the trace and Frobenius norms, the density matrix that is farthest from the set of l…

Universal initial state preparation for first quantized quantum simulations
Jack S. Baker, Gaurav Saxena, Thi Ha Kyaw
https://arxiv.org/abs/2510.07278 https://

Universal initial state preparation for first quantized quantum simulations
Preparing symmetry-adapted initial states is a principal bottleneck in first-quantized quantum simulation. We present a universal approach that efficiently maps any polynomial-size superposition of occupation-number configurations to the first-quantized representation on a digital quantum computer. The method exploits the Jordan--Schwinger Lie algebra homomorphism, which identifies number-conserving second-quantized operators with their first-quantized action and induces an equivariant bijectio…

Shedding light on classical shadows: learning photonic quantum states
Hugo Thomas, Ulysse Chabaud, Pierre-Emmanuel Emeriau
https://arxiv.org/abs/2510.07240 https://

Shedding light on classical shadows: learning photonic quantum states
Efficient learning of quantum state properties is both a fundamental and practical problem in quantum information theory. Classical shadows have emerged as an efficient method for estimating properties of unknown quantum states, with rigorous statistical guarantees, by performing randomized measurement on a few number of copies. With the advent of photonic technologies, formulating efficient learning algorithms for such platforms comes out as a natural problem. Here, we introduce a classical sh…

Efficient Convex Optimization for Bosonic State Tomography
Shengyong Li, Yanjin Yue, Ying Hu, Rui-Yang Gong, Qianchuan Zhao, Zhihui Peng, Pengtao Song, Zeliang Xiang, Jing Zhang
https://arxiv.org/abs/2509.06305

Efficient Convex Optimization for Bosonic State Tomography
Quantum states encoded in electromagnetic fields, also known as bosonic states, have been widely applied in quantum sensing, quantum communication, and quantum error correction. Accurate characterization is therefore essential yet difficult when states cannot be reconstructed with sparse Pauli measurements. Tomography must work with dense measurement bases, high-dimensional Hilbert spaces, and often sample-based data. However, existing convex optimization-based techniques are not efficient enou…

Is it Gaussian? Testing bosonic quantum states
Filippo Girardi, Freek Witteveen, Francesco Anna Mele, Lennart Bittel, Salvatore F. E. Oliviero, David Gross, Michael Walter
https://arxiv.org/abs/2510.07305

Is it Gaussian? Testing bosonic quantum states
Gaussian states are widely regarded as one of the most relevant classes of continuous-variable (CV) quantum states, as they naturally arise in physical systems and play a key role in quantum technologies. This motivates a fundamental question: given copies of an unknown CV state, how can we efficiently test whether it is Gaussian? We address this problem from the perspective of representation theory and quantum learning theory, characterizing the sample complexity of Gaussianity testing as a fu…

Unitary Quantum Cellular Automata for Density Classification
Pedro C. S. Costa, Yuval R. Sanders, Pedro Paulo Balbi, Gavin K. Brennen
https://arxiv.org/abs/2510.06947 https://…

Unitary Quantum Cellular Automata for Density Classification
We investigate the density classification task (DCT) -- determining the majority bit in a one-dimensional binary lattice -- within a quantum cellular automaton (CA) framework. While there is no one-dimensional two-state, radius $r \geq 1$, deterministic CA with periodic boundary conditions that solves the DCT perfectly, we explore whether a unitary quantum model can succeed. We employ the Partitioned Unitary Quantum Cellular Automaton (PUQCA), a number-conserving model, and, via evolutionary se…

Fine-Grained Unambiguous Measurements
Quentin Buzet, Andr\'e Chailloux
https://arxiv.org/abs/2510.07298 https://arxiv.org/pdf/2510.07298

Fine-Grained Unambiguous Measurements
Unambiguous measurements play an important role in quantum information, with applications ranging from quantum key distribution to quantum state reconstruction. Recently, such measurements have also been used in quantum algorithms based on Regev's reduction. The key problem for these algorithms is the S-LWE problem for lattice problems, or the Quantum Decoding Problem for code problems. A key idea for addressing this problem is to use unambiguous measurements to recover $k$ coordinates of a cod…

Block encoding the 3D heterogeneous Poisson equation with application to fracture flow
Austin Pechan, John Golden, Daniel O'Malley
https://arxiv.org/abs/2508.07125 https://

Block encoding the 3D heterogeneous Poisson equation with application to fracture flow
Quantum linear system (QLS) algorithms offer the potential to solve large-scale linear systems exponentially faster than classical methods. However, applying QLS algorithms to real-world problems remains challenging due to issues such as state preparation, data loading, and efficient information extraction. In this work, we study the feasibility of applying QLS algorithms to solve discretized three-dimensional heterogeneous Poisson equations, with specific examples relating to groundwater flow …

Revisiting intrinsic spin defects in hexagonal boron nitride with r2SCAN
Petros-Panagis Filippatos, Tom J. P. Irons, Katherine Inzani
https://arxiv.org/abs/2509.09002 https://…

Revisiting intrinsic spin defects in hexagonal boron nitride with r2SCAN
Hexagonal boron nitride (hBN) is a wide band gap, van der Waals material that is highly promising for solid-state quantum technologies as a host of optically addressable, paramagnetic spin defects. Intrinsic and extrinsic point defects provide a range of emission energies, but the atomic-level structures related to observed transitions are not fully characterised. In this work, intrinsic point defects in bulk hBN are modelled using density functional theory at the level of the meta-generalized …

Photon Statistics for Fock and Coherent States Interfering in a Beamsplitter
Jhordan A. T. Santiago
https://arxiv.org/abs/2508.08223 https://arxiv.org/pdf/…

Photon Statistics for Fock and Coherent States Interfering in a Beamsplitter
We present a straightforward yet comprehensive theoretical study of different quantum states emerging from a bi-modal beamsplitter when various input states interfere. Specifically, we analyze the output states for different combinations of input fields, including Fock states $|n\rangle|m\rangle$, hybrid states $|n\rangle|α\rangle$, and coherent states $|α\rangle|β\rangle$. We derive explicit expressions for the output state vectors, calculate the mean photon nu…

Geometry-Controlled Freezing and Revival of Bell Nonlocality through Environmental Memory
Mohamed Hatifi
https://arxiv.org/abs/2508.07046 https://arxiv.org…

Geometry-Controlled Freezing and Revival of Bell Nonlocality through Environmental Memory
We show that the distance between two qubits coupled to a structured reservoir acts as a single geometric control that can store, revive, or suppress Bell nonlocality. In a mirror-terminated guide, quantum correlations lost to the bath return at discrete recurrence times, turning a product state into a Bell-violating one without any entangling drive (only local basis rotations/readout). In the continuum limit, we derive closed-form criteria for the emergence of nonlocality from backflow, and in…

Absence of quantum Darwinism as a resource in secure quantum communication and computation
Bishal Kumar Das, Sourav Manna, Vaibhav Madhok
https://arxiv.org/abs/2510.03225 https:…

Absence of quantum Darwinism as a resource in secure quantum communication and computation
The emergence of classical world from underlying quantum mechanics is characterized by not only vanishing quantum correlations but also an unfolding of objectivity also known as quantum Darwinism. We show that the absence of this objectivity has a quantum advantage in cryptography and also provides the crucial missing link in efficient classical simulation of quantum circuits with zero discord. For this purpose, we consider a model of mixed state quantum computation where one is promised concor…

Entanglement phases and phase transitions in monitored free fermion system due to localizations
Yu-Jun Zhao, Xuyang Huang, Yi-Rui Zhang, Han-Ze Li, Jian-Xin Zhong
https://arxiv.org/abs/2509.09538

Entanglement phases and phase transitions in monitored free fermion system due to localizations
In recent years, the presence of local potentials has significantly enriched and diversified the entanglement patterns in monitored free fermion systems. In our approach, we employ the stochastic Schrödinger equation to simulate a one-dimensional spinless fermion system under continuous measurement and local potentials. By averaging the steady-state entanglement entropy over many quantum trajectories, we investigate its dependence on measurement and localization parameters. We used a phenomeno…

Recovery of the second law in fully quantum thermodynamics
Naoto Shiraishi, Ryuji Takagi
https://arxiv.org/abs/2510.05642 https://arxiv.org/pdf/2510.05642

Recovery of the second law in fully quantum thermodynamics
Quantum thermodynamics investigates how robust the second law of thermodynamics serves as the unique fundamental law in the small quantum world. To tackle this problem, the quantum coherence constitutes a major difficulty of investigations, which provides severe constraints hindering the recovery of a single thermodynamic potential. Here we solve this long-standing problem of quantum information theory by revealing that the state convertibility under thermal operations is fully characterized by…

Quantum Replica Exchange
Zherui Chen, Joao Basso, Zhiyan Ding, Lin Lin
https://arxiv.org/abs/2510.07291 https://arxiv.org/pdf/2510.07291

Quantum Replica Exchange
The presence of energy barriers in the state space of a physical system can lead to exponentially slow convergence for sampling algorithms like Markov chain Monte Carlo (MCMC). In the classical setting, replica exchange (or parallel tempering) is a powerful heuristic to accelerate mixing in these scenarios. In the quantum realm, preparing Gibbs states of Hamiltonians faces a similar challenge, where bottlenecks can dramatically increase the mixing time of quantum dynamical semigroups. In this w…

Beyond Stellar Rank: Control Parameters for Scalable Optical Non-Gaussian State Generation
Fumiya Hanamura, Kan Takase, Hironari Nagayoshi, Ryuhoh Ide, Warit Asavanant, Kosuke Fukui, Petr Marek, Radim Filip, Akira Furusawa
https://arxiv.org/abs/2509.06255

Beyond Stellar Rank: Control Parameters for Scalable Optical Non-Gaussian State Generation
Advanced quantum technologies rely on non-Gaussian states of light, essential for universal quantum computation, fault-tolerant error correction, and quantum sensing. Their practical realization, however, faces hurdles: simulating large multi-mode generators is computationally demanding, and benchmarks such as the \emph{stellar rank} do not capture how effectively photon detections yield useful non-Gaussianity. We address these challenges by introducing the \emph{non-Gaussian control parameters…

HPQEA: A Scalable and High-Performance Quantum Emulator with High-Bandwidth Memory for Diverse Algorithms Support
Tran Van Duy, Tuan Hai Vu, Vu Trung Duong Le, Hoai Luan Pham, Yasuhiko Nakashima
https://arxiv.org/abs/2510.07110

HPQEA: A Scalable and High-Performance Quantum Emulator with High-Bandwidth Memory for Diverse Algorithms Support
In recent years, there has been a growing interest in the development of quantum emulation. However, existing studies often struggle to achieve broad applicability, high performance, and efficient resource and memory utilization. To address these challenges, we provide HPQEA, a quantum emulator based on the state-vector emulation approach. HPQEA includes three main features: a high-performance computing core, an optimized controlled-NOT gate computation strategy, and effective utilization of hi…

Quantum Zeno effect versus adiabatic quantum computing and quantum annealing
Naser Ahmadiniaz, Dennis Kraft, Gernot Schaller, Ralf Sch\"utzhold
https://arxiv.org/abs/2509.04057

Quantum Zeno effect versus adiabatic quantum computing and quantum annealing
For the adiabatic version of Grover's quantum search algorithm as proposed by Roland and Cerf, we study the impact of decoherence caused by a rather general coupling to some environment. For quite generic conditions, we find that the quantum Zeno effect poses strong limitations on the performance (quantum speed-up) since the environment effectively measures the state of the system permanently and thereby inhibits or slows down quantum transitions. Generalizing our results, we find that analogou…

How hard is it to verify a classical shadow?
Georgios Karaiskos, Dorian Rudolph, Johannes Jakob Meyer, Jens Eisert, Sevag Gharibian
https://arxiv.org/abs/2510.08515 https://

How hard is it to verify a classical shadow?
Classical shadows are succinct classical representations of quantum states which allow one to encode a set of properties P of a quantum state rho, while only requiring measurements on logarithmically many copies of rho in the size of P. In this work, we initiate the study of verification of classical shadows, denoted classical shadow validity (CSV), from the perspective of computational complexity, which asks: Given a classical shadow S, how hard is it to verify that S predicts the measurement …

Fermionic Insights into Measurement-Based Quantum Computation: Circle Graph States Are Not Universal Resources
Brent Harrison, Vishnu Iyer, Ojas Parekh, Kevin Thompson, Andrew Zhao
https://arxiv.org/abs/2510.05557

Fermionic Insights into Measurement-Based Quantum Computation: Circle Graph States Are Not Universal Resources
Measurement-based quantum computation (MBQC) is a strong contender for realizing quantum computers. A critical question for MBQC is the identification of resource graph states that can enable universal quantum computation. Any such universal family must have unbounded entanglement width, which is known to be equivalent to the ability to produce any circle graph state from the states in the family using only local Clifford operations, local Pauli measurements, and classical communication. Yet, i…

Optimal Distillation of Qubit Clocks
Sujay Kazi, Iman Marvian
https://arxiv.org/abs/2510.08493 https://arxiv.org/pdf/2510.08493

Optimal Distillation of Qubit Clocks
We study coherence distillation under time-translation-invariant operations: given many copies of a quantum state containing coherence in the energy eigenbasis, the aim is to produce a purer coherent state while respecting the time-translation symmetry. This symmetry ensures that the output remains synchronized with the input and that the process can be realized by energy-conserving unitaries coupling the system to a reservoir initially in an energy eigenstate, thereby modeling thermal operatio…

Rapid Mixing of Quantum Gibbs Samplers for Weakly-Interacting Quantum Systems
\v{S}t\v{e}p\'an \v{S}m\'id, Richard Meister, Mario Berta, Roberto Bondesan
https://arxiv.org/abs/2510.04954

Rapid Mixing of Quantum Gibbs Samplers for Weakly-Interacting Quantum Systems
Dissipative quantum algorithms for state preparation in many-body systems are increasingly recognised as promising candidates for achieving large quantum advantages in application-relevant tasks. Recent advances in algorithmic, detailed-balance Lindbladians enable the efficient simulation of open-system dynamics converging towards desired target states. However, the overall complexity of such schemes is governed by system-size dependent mixing times. In this work, we analyse algorithmic Lindbla…

A Class of Cyclic Quantum Codes
Matthew B. Hastings
https://arxiv.org/abs/2509.06865 https://arxiv.org/pdf/2509.06865…

A Class of Cyclic Quantum Codes
We introduce a class of cyclic quantum codes, basing the construction not on the simplicity of the stabilizers, but rather on the simplicity of preparation of a code state (at least in the absence of noise). We show how certain known codes, such as a certain family of rotated two-dimensional toric codes, fall into this class, and we also give certain other examples at small sizes found by computer search. We finally discuss fault tolerant preparation of these codes.

Interfacing Quantum Computing Systems with High-Performance Computing Systems: An Overview
Konstantinos Rallis, Ioannis Liliopoulos, Georgios D. Varsamis, Evangelos Tsipas, Ioannis G. Karafyllidis, Georgios Ch. Sirakoulis, Panagiotis Dimitrakis
https://arxiv.org/abs/2509.06205

Interfacing Quantum Computing Systems with High-Performance Computing Systems: An Overview
The connection and eventual integration of High-Performance Computing (HPC) with Quantum Computing (QC) represents a transformative advancement in computational technology, promising significant enhancements in solving complex, previously intractable problems. This manuscript provides a comprehensive overview of the current state of HPC-QC interfacing, detailing architectural methodologies, software stack developments, middleware functionalities, and hardware integration strategies. It critical…

Utility-Scale Quantum State Preparation: Classical Training using Pauli Path Simulation
Cheng-Ju Lin, Hrant Gharibyan, Vincent P. Su
https://arxiv.org/abs/2510.02428 https://

Utility-Scale Quantum State Preparation: Classical Training using Pauli Path Simulation
We use Pauli Path simulation to variationally obtain parametrized circuits for preparing ground states of various quantum many-body Hamiltonians. These include the quantum Ising model in one dimension, in two dimensions on square and heavy-hex lattices, and the Kitaev honeycomb model, all at system sizes of one hundred qubits or more, beyond the reach of exact state-vector simulation, thereby reaching utility scale. We benchmark the Pauli Path simulation results against exact ground-state energ…

Quantum approximate optimization of bosonic finite-state systems
Shakib Daryanoosh
https://arxiv.org/abs/2510.05576 https://arxiv.org/pdf/2510.05576…

Quantum approximate optimization of bosonic finite-state systems
There exist numerous problems in nature inherently described by finite $D$-dimensional states. Formulating these problems for execution on qubit-based quantum hardware requires mapping the qudit Hilbert space to that of multiqubit which may be exponentially larger. To exclude the infeasible subspace, one common approach relies on penalizing the objective function. However, this strategy can be inefficient as the size of the illegitimate subspace grows. Here we propose to employ the Hamiltonian-…

Learning stabilizer structure of quantum states
Srinivasan Arunachalam, Arkopal Dutt
https://arxiv.org/abs/2510.05890 https://arxiv.org/pdf/2510.05890

Learning stabilizer structure of quantum states
We consider the task of learning a structured stabilizer decomposition of an arbitrary $n$-qubit quantum state $|ψ\rangle$: for $\varepsilon > 0$, output a state $|ϕ\rangle$ with stabilizer-rank $\textsf{poly}(1/\varepsilon)$ such that $|ψ\rangle=|ϕ\rangle+|ϕ'\rangle$ where $|ϕ'\rangle$ has stabilizer fidelity $< \varepsilon$. We firstly show the existence of such decompositions using the recently established inverse theorem for the Gowers-$3$ norm of states …

A New Quantum Linear System Algorithm Beyond the Condition Number and Its Application to Solving Multivariate Polynomial Systems
Jianqiang Li
https://arxiv.org/abs/2510.05588 ht…

A New Quantum Linear System Algorithm Beyond the Condition Number and Its Application to Solving Multivariate Polynomial Systems
Given a matrix $A$ of dimension $M \times N$ and a vector $\vec{b}$, the quantum linear system (QLS) problem asks for the preparation of a quantum state $|\vec{y}\rangle$ proportional to the solution of $A\vec{y} = \vec{b}$. Existing QLS algorithms have runtimes that scale linearly with the condition number $κ(A)$, the sparsity of $A$, and logarithmically with inverse precision, but often overlook structural properties of $\vec{b}$, whose alignment with $A$'s eigenspaces can greatly affec…

Collective dissipation engineering of interacting Rydberg atoms
Tao Chen, Chenxi Huang, Jacob P. Covey, Bryce Gadway
https://arxiv.org/abs/2509.06373 https://

Collective dissipation engineering of interacting Rydberg atoms
Engineered dissipation is emerging as an alternative tool for quantum state control, enabling high-fidelity preparation, transfer and stabilization, and access to novel phase transitions. We realize a tunable, state-resolved laser-induced loss channel for individual Rydberg atoms, in both non-interacting and strongly correlated settings. This capability allows us to reveal interaction-driven shifts of the exceptional point separating quantum Zeno and anti-Zeno regimes, and to demonstrate intera…

Entangling remote qubits through a two-mode squeezed reservoir
A. Andr\'es-Juanes, J. Agust\'i, R. Sett, E. S. Redchenko, L. Kapoor, S. Hawaldar, P. Rabl, J. M. Fink
https://arxiv.org/abs/2510.07139

Entangling remote qubits through a two-mode squeezed reservoir
The distribution of entanglement across distant qubits is a central challenge for the operation of scalable quantum computers and large-scale quantum networks. Existing approaches rely on deterministic state transfer schemes or probabilistic protocols that require active control or measurement and postselection. Here we demonstrate an alternative, fully autonomous process, where two remote qubits are entangled through their coupling to a quantum-correlated photonic reservoir. In our experiment,…

Magic and communication complexity
Uma Girish, Alex May, Natalie Parham, Henry Yuen
https://arxiv.org/abs/2510.07246 https://arxiv.org/pdf/2510.07246

Magic and communication complexity
We establish novel connections between magic in quantum circuits and communication complexity. In particular, we show that functions computable with low magic have low communication cost. Our first result shows that the $\mathsf{D}\|$ (deterministic simultaneous message passing) cost of a Boolean function $f$ is at most the number of single-qubit magic gates in a quantum circuit computing $f$ with any quantum advice state. If we allow mid-circuit measurements and adaptive circuits, we ob…

Quantum Filtering at Finite Temperature
John Gough
https://arxiv.org/abs/2510.04967 https://arxiv.org/pdf/2510.04967

Quantum Filtering at Finite Temperature
We pose and solve the problem of quantum filtering based on continuous-in-time quadrature measurements (homodyning) for the case where the quantum process is in a thermal state. The standard construction of quantum filters involves the determination of the conditional expectation onto the von Neumann algebra generated by the measured observables with the non-demolition principle telling us to restrict the domain (the observables to be estimated) to the commutant of the algebra. The finite-tempe…

Adiabatic preparation of thermal states and entropy-noise relation on noisy quantum computers
Etienne Granet, Henrik Dreyer
https://arxiv.org/abs/2509.05206 https://

Adiabatic preparation of thermal states and entropy-noise relation on noisy quantum computers
We consider the problem of preparing thermal equilibrium states at finite temperature on quantum computers. Assuming thermalization, we show that states that are locally at thermal equilibrium can be prepared by evolving adiabatically an initial thermal Gibbs state of a simple Hamiltonian with an interpolating time-dependent Hamiltonian, identically to adiabatic ground state preparation. We argue that the entropy density of local density matrices is conserved during the adiabatic evolution, so …

Histogram Driven Amplitude Embedding for Qubit Efficient Quantum Image Compression
Sahil Tomar, Sandeep Kumar
https://arxiv.org/abs/2509.04849 https://arxi…

Histogram Driven Amplitude Embedding for Qubit Efficient Quantum Image Compression
This work introduces a compact and hardware efficient method for compressing color images using near term quantum devices. The approach segments the image into fixed size blocks called bixels, and computes the total intensity within each block. A global histogram with B bins is then constructed from these block intensities, and the normalized square roots of the bin counts are encoded as amplitudes into an n qubit quantum state. Amplitude embedding is performed using PennyLane and executed on r…

Quantum metrology through spectral measurements in quantum optics
Alejandro Vivas-Via\~na, Carlos S\'anchez Mu\~noz
https://arxiv.org/abs/2509.04300 https://

Quantum metrology through spectral measurements in quantum optics
Continuously monitored quantum systems are emerging as promising platforms for quantum metrology, where a central challenge is to identify measurement strategies that optimally extract information about unknown parameters encoded in the complex quantum state of emitted radiation. Different measurement strategies effectively access distinct temporal modes of the emitted field, and the resulting choice of mode can strongly impact the information available for parameter estimation. While a ubiquit…

Optimizaci\'on de la Transmisi\'on de Estados Cu\'anticos en Cadenas de Qubits usando Deep Reinforcement Learning y Algoritmos Gen\'eticos
Sof\'ia Per\'on Santana, Ariel Fiuri, Omar Osenda, Mart\'in Dom\'inguez
https://arxiv.org/abs/2510.05010

Optimización de la Transmisión de Estados Cuánticos en Cadenas de Qubits usando Deep Reinforcement Learning y Algoritmos Genéticos
Quantum state transfer (QST) via homogeneous spin chains plays a crucial role in building scalable quantum hardware. A basic quantum state transmission protocol prepares a state in one qubit and transfers it to another through a channel, seeking to minimize the time and avoid information loss. The fidelity of the process is measured by functions proportional to the transition probability between both states. We approach this optimization problem using constant magnetic pulses and two complement…

Amplitude-based Input Attribution in Quantum Learning via Integrated Gradients
Nicholas S. DiBrita, Jason Han, Younghyun Cho, Hengrui Luo, Tirthak Patel
https://arxiv.org/abs/2510.02497

Amplitude-based Input Attribution in Quantum Learning via Integrated Gradients
Quantum machine learning (QML) algorithms have demonstrated early promise across hardware platforms, but remain difficult to interpret due to the inherent opacity of quantum state evolution. Widely used classical interpretability methods, such as integrated gradients and surrogate-based sensitivity analysis, are not directly compatible with quantum circuits due to measurement collapse and the exponential complexity of simulating state evolution. In this work, we introduce HATTRIQ, a general-pur…

Replaced article(s) found for quant-ph. https://arxiv.org/list/quant-ph/new
[1/3]:
- Quantum State Smoothing for Linear Gaussian Systems
Kiarn T. Laverick, Areeya Chantasri, Howard M. Wiseman

Response of a classical mesoscopic oscillator to a two-level quantum system
Felipe Sobrero, Luca Abrah\~ao, Thiago Guerreiro, Pedro V. Paraguass\'u
https://arxiv.org/abs/2509.04216

Response of a classical mesoscopic oscillator to a two-level quantum system
We investigate the dynamics of a classical mechanical oscillator coupled to the simplest quantum system, a single qubit. The qubit's influence manifests as deterministic and stochastic forces, highly dependent on its initial quantum state, imprinting unique measurable quantum-induced signatures onto the oscillator's response. The present results suggest a pathway to quantum state reconstruction through classical noise spectroscopy, with potential applications to mesoscopic optomechanical experi…