Tootfinder

Model-based framework for automated quantification of error sources in quantum state tomography
Junpei Oba, Hsin-Pin Lo, Yasuhiro Yamada, Takayuki Matsui, Takuya Ikuta, Yuya Yonezu, Toshimori Honjo, Seiji Kajita, Hiroki Takesue
https://arxiv.org/abs/2508.05538

Model-based framework for automated quantification of error sources in quantum state tomography
High-quality quantum state generation is essential for advanced quantum information processing, including quantum communication, quantum sensing, and quantum computing. In practice, various error sources degrade the quality of quantum states, and quantum state tomography (QST) is a standard diagnostic tool. However, in QST, multiple error sources gather in a single density matrix, making it difficult to identify individual error sources. To address this problem, we propose an automated method f…

Quantum State Preparation Of Multiconfigurational States For Quantum Chemistry
Gabriel Greene-Diniz, Georgia Prokopiou, David Zsolt Manrique, David Mu\~noz Ramo
https://arxiv.org/abs/2508.05390

Quantum State Preparation Of Multiconfigurational States For Quantum Chemistry
The ability to prepare states for quantum chemistry is a promising feature of quantum computers, and efficient techniques for chemical state preparation is an active area of research. In this paper, we implement and investigate two methods of quantum circuit preparation for multiconfigurational states for quantum chemical applications. It has previously been shown that controlled Givens rotations are universal for quantum chemistry. To prepare a selected linear combination of Slater determinant…

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…

Symmetry Resolved Entanglement Entropy in a Non-Abelian Fractional Quantum Hall State
Mark J. Arildsen, Valentin Cr\'epel, Nicolas Regnault, Benoit Estienne
https://arxiv.org/abs/2508.05494

Symmetry Resolved Entanglement Entropy in a Non-Abelian Fractional Quantum Hall State
Symmetry-resolved entanglement entropy provides a powerful framework for probing the internal structure of quantum many-body states by decomposing entanglement into contributions from distinct symmetry sectors. In this work, we apply matrix product state techniques to study the bosonic, non-Abelian Moore-Read quantum Hall state, enabling precise numerical evaluation of both the full counting statistics and symmetry-resolved entanglement entropies. Our results reveal an approximate equipartition…

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…

Visualising Quantum Entanglement Using Interactive Electronic Quantum Dice
B. Folkers, A. van Rossum, A. Brinkman, H. K. E. Stadermann
https://arxiv.org/abs/2510.04931 https://

Visualising Quantum Entanglement Using Interactive Electronic Quantum Dice
Quantum entanglement is difficult to teach because it is microscopic and non classical. We present interactive electronic dice that simulate core quantum ideas through haptic interaction and visual feedback. Each die represents a six state system with a superposition display and basis dependent measurement. A pair of dice can be prepared in an entangled mode that yields anti correlated outcomes which sum to seven when measured in the same colour basis while remaining uncorrelated across differe…

Exact Quench Dynamics from Thermal Pure Quantum States
Hui-Huang Chen
https://arxiv.org/abs/2510.05346 https://arxiv.org/pdf/2510.05346

Exact Quench Dynamics from Thermal Pure Quantum States
We present an exact solution for a quantum quench in an integrable system that reveals a new, coherent pathway to thermalization. In chaotic systems, thermalization is understood via the eigenstate thermalization hypothesis (ETH), which implies that a quench from a thermal pure quantum (TPQ) state should exhibit trivial dynamics. In contrast, integrable systems are expected to retain memory of their initial conditions in a non-thermal generalized Gibbs ensemble (GGE). We show that a quench from…

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…

Polynomial Prethermal Lifetimes in Non Smoothly Driven Quantum Systems
Matteo Gallone, Beatrice Langella
https://arxiv.org/abs/2510.04137 https://arxiv.org…

Polynomial Prethermal Lifetimes in Non Smoothly Driven Quantum Systems
We study the dynamics of a quantum many-body lattice system with a local Hamiltonian subjected to a quasi-periodic driving with finite regularity. For sufficiently large driving frequencies, we prove that the system remains in a prethermal state for times growing polynomially with the frequency, and we show the optimality of this bound by constructing an explicit example that nearly saturates it. Within this prethermal regime, the dynamics is captured by an effective time-independent local Hami…

Quantum Lattice Boltzmann Method for Multiple Time Steps Without Reinitialization for Linear Advection-Diffusion Problems
Aaron Nagel, Johannes L\"owe
https://arxiv.org/abs/2510.05965

Quantum Lattice Boltzmann Method for Multiple Time Steps Without Reinitialization for Linear Advection-Diffusion Problems
To simulate highly-resolved flow fields, we extend the Quantum Lattice Boltzmann Method (QLBM) to be able to simulate multiple time steps without state extraction or reinitialization. We adjust and extend given QLBM approaches from the literature to completely remove the need to measure or reinitialize the flow field in between the simulation time steps. Therefore, our algorithm does not require to sample the entire flow field at any time. We solve the linear advection-diffusion problem and der…

Qubit entanglement from forward scattering
Kamila Kowalska, Enrico Maria Sessolo
https://arxiv.org/abs/2510.04200 https://arxiv.org/pdf/2510.04200

Qubit entanglement from forward scattering
In the context of entanglement in relativistic $2\to 2$ scattering described by a perturbative $S$-matrix, we derive analytically the concurrence for a mixed final state of two qubits corresponding to a discrete quantum number of the scattered particles. Given an initial product state, the derived concurrence depends at the leading order on the real part of the inelastic forward amplitude and the initial state only. We also point out that the real part of the forward amplitude provides a sublea…

Quantum walks on finite and bounded infinite graphs
Chris Godsil, Steve Kirkland, Sarojini Mohapatra, Hermie Monterde, Hiranmoy Pal
https://arxiv.org/abs/2510.05306 https://

Quantum walks on finite and bounded infinite graphs
A weighted graph $G$ with countable vertex set is bounded if there is an upper bound on the maximum of the sum of absolute values of all edge weights incident to a vertex in $G$. In this paper, we prove a fundamental result on equitable partitions of bounded weighted graphs with twin subgraphs and use this fact to construct finite and bounded infinite graphs with pair and plus state transfer with the adjacency matrix as a Hamiltonian. We show that for each $k \ge 3$, (i) there are infinitely ma…

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…

Regular black holes and boson stars in semiclassical gravity
Irfan Javed, Viqar Husain
https://arxiv.org/abs/2510.03935 https://arxiv.org/pdf/2510.03935

Regular black holes and boson stars in semiclassical gravity
We use a Hamiltonian version of the semiclassical Einstein equation to study classical gravity coupled to a quantum scalar field with potential in spherical symmetry. The system is defined by effective constraints where the matter terms are replaced by their expectation values in a quantum state. For the static case, we find numerically that the resulting equations admit asymptotically flat, de Sitter, and anti-de Sitter boson star and regular black hole solutions. We also show that the Bardeen…

DH-EAC: Design of a Dynamic, Hierarchical Entanglement Access Control Protocol
Akihisa Takahashi, Yoshito Tobe
https://arxiv.org/abs/2510.02895 https://arx…

DH-EAC: Design of a Dynamic, Hierarchical Entanglement Access Control Protocol
We propose Dynamic, Hierarchical Entanglement Access Control (DH-EAC), a pure-quantum protocol for fair and anonymous allocation of scarce entanglement across wide-area quantum networks composed of many quantum LANs (QLANs). Prior Dicke-state-based pure-quantum MACs resolve contention by local measurements without classical signaling, but they mainly target a single QLAN under static conditions; extending them to wide-area, dynamic settings while avoiding post-selection reconciliation remains o…

Quantum Emission in Monolayer WSe2 Transferred onto InP Nanowires
Palwinder Singh, Jasleen Kaur Jagde, Megha Jain, Edith Yeung, David B. Northeast, Simona Moisa, Seid J. Mohammed, Jean Lapointe, Una Rajnis, Annika Kienast, Philip J. Poole, Dan Dalacu, Kimberley C. Hall
https://arxiv.org/abs/2510.04198

Quantum Emission in Monolayer WSe2 Transferred onto InP Nanowires
Localized quantum emitters in transition-metal dichalcogenides (TMDs) have recently emerged as solid-state candidates for on-demand sources of single photons. Due to the role of strain in the site-selective creation of TMD emitters, their hybrid integration into photonic structures such as cavities and waveguides is possible using pick-and-place methods. Here we investigate quantum emission from a hybrid structure consisting of a monolayer of WSe2 interfaced with horizontally aligned InP nanowi…

Resource-Efficient Synthesis of Sparse Quantum States
Renaud Vilmart, Sunheang Ty, Chetra Mang
https://arxiv.org/abs/2508.05386 https://arxiv.org/pdf/2508.…

Resource-Efficient Synthesis of Sparse Quantum States
Preparing a quantum circuit that implements a given sparse state is an important building block that is necessary for many different quantum algorithms. In the context of fault-tolerant quantum computing, the so-called non-Clifford gates are much more expensive to perform than the Clifford ones. We hence provide an algorithm for synthesizing sparse quantum states with a special care for quantum resources. The circuit depth, ancilla count, and crucially non-Clifford count of the circuit produced…

A systematic search for conformal field theories in very small spaces
Xiang Li, Ting-Chun Lin, John McGreevy
https://arxiv.org/abs/2509.04596 https://arxiv…

A systematic search for conformal field theories in very small spaces
Groundstates of 1+1d conformal field theories (CFTs) satisfy a local entropic condition called the vector fixed point equation. This condition is surprisingly well satisfied by groundstates of quantum critical lattice models even at small system sizes. We perform a search in the space of states of very small systems (four qubits and four qutrits) and examine the states that satisfy this condition. By reconstructing a local Hamiltonian from each state, we are able to identify many of these solut…

Mind the Gap: From Resolving Theoretical Foundations of Chiral(ity)-Induced Spin Selectivity to Pioneering Implementations in Quantum Sensing
Yan Xi Foo, Aisha Kermiche, Farhan T. Chowdhury, Clarice D. Aiello, Luke D. Smith
https://arxiv.org/abs/2508.05611

Mind the Gap: From Resolving Theoretical Foundations of Chiral(ity)-Induced Spin Selectivity to Pioneering Implementations in Quantum Sensing
The chiral(ity)-induced spin selectivity (CISS) effect, where electrons passing through a chiral medium acquire significant spin-polarization at ambient temperatures, has been widely observed experimentally, yet its theoretical foundations remain actively debated. Open questions persist regarding whether CISS originates from helical geometry or more general chirality, and whether a unified mechanism can account for phenomena across solid-state and soft-matter systems, mesoscopic films, and sing…

“It’s Its Own New Thing” – Scientists Discover New State of Quantum Matter
https://scitechdaily.com/its-its-own-new-thing-scientists-discover-new-state-of-quantum-matter/

Defects in hexagonal boron nitride for quantum technologies
Tobias Vogl, Viktor Iv\'ady, Isaac J. Luxmoore, Hannah L. Stern
https://arxiv.org/abs/2510.04344 https://

Defects in hexagonal boron nitride for quantum technologies
Atomic defects in solid-state materials are building blocks for future quantum technologies, such as quantum communication networks, computers, and sensors. Until recently, a handful of defects in a small selection of host materials have been possible candidates. Recent developments have revealed that hexagonal boron nitride, a wide-bandgap two-dimensional material, hosts single-photon-emitting atomic defects with access to optically addressable electronic and nuclear spins at room temperature.…

Quantum many-body scarring from Kramers-Wannier duality
Weslei B. Fontana, Fabrizio G. Oliviero, Yi-Ping Huang
https://arxiv.org/abs/2508.05403 https://arx…

Quantum many-body scarring from Kramers-Wannier duality
Kramers-Wannier duality, a hallmark of the Ising model, has recently gained renewed interest through its reinterpretation as a non-invertible symmetry with a state-level action. Using sequential quantum circuits (SQC), we argue that this duality governs the stability of quantum many-body scar (QMBS) states in a nonintegrable model, depending on whether the dual preserves the embedding conditions for scarring. This is supported by striking agreement between first-order perturbation theory and nu…

I think the best summary until now about Post-quantum cryptography is from Peter Gutmann in the cryptography mailing-list.

Given that after 20 years and hundreds of millions of dollars spent researchers have yet to demonstrate a single legitimate cryptanalysis result using a quantum physics experiment, it's a bit like arguing over which brand of unicorn repellent is the most cromulent.

The current state of things in terms of pure vs. hybrid systems seems to be:

- …

Resting-state fMRI Analysis using Quantum Time-series Transformer
Junghoon Justin Park, Jungwoo Seo, Sangyoon Bae, Samuel Yen-Chi Chen, Huan-Hsin Tseng, Jiook Cha, Shinjae Yoo
https://arxiv.org/abs/2509.00711

Resting-state fMRI Analysis using Quantum Time-series Transformer
Resting-state functional magnetic resonance imaging (fMRI) has emerged as a pivotal tool for revealing intrinsic brain network connectivity and identifying neural biomarkers of neuropsychiatric conditions. However, classical self-attention transformer models--despite their formidable representational power--struggle with quadratic complexity, large parameter counts, and substantial data requirements. To address these barriers, we introduce a Quantum Time-series Transformer, a novel quantum-enha…

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…

High-Efficiency Quantum-State Detection of ThF$^ $ with Resonance-Enhanced Multiphoton Asymmetric Dissociation
Kia Boon Ng, Sun Yool Park, Anzhou Wang, Addison Hartman, Patricia Hector Hernandez, Rohan Kompella, Lan Cheng, Stephan Malbrunot-Ettenauer, Jun Ye, Eric A. Cornell
https://arxiv.org/abs/2508.04949…

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…

Multiple quantum spin Hall states and topological current divider in Twisted Bilayer WSe$_2$
Hao He, Zhao Gong, Shuai Li, Jian-Jun Liu, Hui-Ying Mu, Xing-Tao An
https://arxiv.org/abs/2508.05092

Multiple quantum spin Hall states and topological current divider in Twisted Bilayer WSe$_2$
It has been demonstrated that topological quantum spin Hall (QSH) state exist in twisted bilayers of transition metal dichalcogenides. However, a comprehensive theoretical characterization of the topological edge states remains a topic of interest and an unresolved issue. Here, the topological transport properties of the twisted WSe$_2$ bilayers are investigated. Beyond the conventional single QSH, we identify emergent double and quartuple quantum spin Hall states, hosting two and four pairs of…

Quantum Computation of the Electronic Structure of Some Prototype Solids
Naman Khandelwal, Nidhi Verma, Pooja Jamdagni, Ashok Kumar
https://arxiv.org/abs/2509.01648 https://

Quantum Computation of the Electronic Structure of Some Prototype Solids
Over the last decade, researchers have been working to improve a crucial aspect of quantum computing to predict Hamiltonian energy of solids. Quantum algorithms such as Variational Quantum Eigensolver (VQE) and Variational Quantum Deflation (VQD) have been used to study the molecular systems. However, there is growing interest in adapting and applying these methods to periodic solid-state materials. In this work, we have integrated first-principles density functional theory with VQE and VQD alg…

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…

Study of Kiselev Black Hole in Quantum Fluctuation Modified Gravity via Quasinormal modes and Greybody Factors
W. Sajjad, M. Azam
https://arxiv.org/abs/2510.02409 https://

Study of Kiselev Black Hole in Quantum Fluctuation Modified Gravity via Quasinormal modes and Greybody Factors
In this work, we formulate the wave function to compute the effective potential of scalar and vector fields for the Kiselve black hole in the background of quantum fluctuation modified gravity. Using the 6th-order Wentzel-Kramers-Brillouin approach, the quasinormal modes for the considered black hole are obtained through scalar and vector perturbation fields. We investigate the quasinormal frequency by considering several values of the metric and equation of state ($\mho$ and $\bar{\barω}$) pa…

The Mpemba Effect in Pure Water Has a Stochastic Origin. Experimental and Theoretical Resolution of the Paradox
Andrei A. Klimov, Alexei V. Finkelstein
https://arxiv.org/abs/2508.05607

The Mpemba Effect in Pure Water Has a Stochastic Origin. Experimental and Theoretical Resolution of the Paradox
The "Mpemba effect" is the name given to the assertion that hot water freezes quicker than cold water1 or, in a modern and more general form, that the system that is initially more distant from its equilibrium state comes to this state earlier2. This counterintuitive statement seems to breach fundamental thermodynamic and kinetic laws; however, numerous experiments3-10 with classical and quantum systems demonstrate this paradoxical Mpemba effect, leading to extensive discssions in prominent sci…

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…

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…

Background Suppression in Quantum Sensing of Dark Matter via $W$ State Projection
Shion Chen, Hajime Fukuda, Yutaro Iiyama, Yuya Mino, Takeo Moroi, Mikio Nakahara, Tatsumi Nitta, Thanaporn Sichanugrist
https://arxiv.org/abs/2510.01816

Background Suppression in Quantum Sensing of Dark Matter via $W$ State Projection
We show that measuring dark matter signal by projecting quantum sensors in the collective excited state can highly suppress the non-collective noise background, hence improving the sensitivity significantly. We trace the evolution of the sensors' state in the presence of both dark matter effect and sensors' decoherence effects, optimizing the protocol execution time, and show that the suppression of background by a factor equal to the number of sensors is possible. This method does not require …

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…

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-…

Bootstrapping supersymmetric (matrix) quantum mechanics
Samuel Laliberte, Brian McPeak
https://arxiv.org/abs/2510.01356 https://arxiv.org/pdf/2510.01356

Bootstrapping supersymmetric (matrix) quantum mechanics
We apply the quantum-mechanics bootstrap to supersymmetric quantum mechanics (SUSY QM) and to its matrix relative, the Marinari-Parisi model, which is conjectured to describe the worldvolume of unstable $D0$ branes. Using positivity of moment matrices together with Heisenberg, gauge, and (zero-temperature) thermal constraints, we obtain rigorous bounds on ground-state data. In the cases where SUSY is spontaneously broken, we find bounds that apply to the lowest-energy normalizable eigenstate. …

Reduced fidelities for free fermions out of equilibrium: From dynamical quantum phase transitions to Mpemba effect
Gilles Parez, Vincenzo Alba
https://arxiv.org/abs/2509.01608 h…

Reduced fidelities for free fermions out of equilibrium: From dynamical quantum phase transitions to Mpemba effect
We investigate the out-of-equilibrium dynamics after a quantum quench of the reduced fidelities between the states of a subregion $A$ at different times. Precisely, we consider the fidelity between the time-dependent state of $A$ and its initial value, as well as with the state at infinite time. We denote these fidelities as the reduced Loschmidt echo (RLE) and the final-state fidelity (FSF), respectively. If region $A$ is the full systems, the RLE coincide with the standard Loschmidt echo. We …

Effective linear response in non-equilibrium anyonic systems
Gu Zhang, Igor Gornyi, Yuval Gefen
https://arxiv.org/abs/2510.03985 https://arxiv.org/pdf/2510…

Effective linear response in non-equilibrium anyonic systems
Linear response theory serves as a fundamental tool in the study of quantum transport, extensively employed to elucidate fundamental mechanisms related to the nature of the particles involved and the underlying symmetries. This framework is, however, limited to equilibrium or near-equilibrium conditions. Here, we develop an effective linear response theory designed to describe charge and thermal quantum transport, where the reference far-from-equilibrium stationary state comprises anyons formin…

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 …

Extreme-ultraviolet laser generation at 118 nm via adaptive random additional periodic-phase engineering in a LiF crystal
Yanling Cheng, Bin Zhang, Fei Liang, Haohai Yu, Huaijin Zhang
https://arxiv.org/abs/2508.05412

Extreme-ultraviolet laser generation at 118 nm via adaptive random additional periodic-phase engineering in a LiF crystal
Extreme ultraviolet (EUV) coherent sources below 120nm are of paramount significance for promoting next-generation nano-scale lithography,precision spectroscopy, and exploring the emerging physical phenomena in quantum materials. Nonlinear optical conversion serves as the only feasible approach to obtain solid state EUV lasers, yet the intrinsic strong absorption at EUV and giant phase mismatch among light waves have hindered the realization of highly-efficient EUV light sources. Herein, we pro…

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…

TeMFpy: a Python library for converting fermionic mean-field states into tensor networks
Simon H. Hille, Attila Szab\'o
https://arxiv.org/abs/2510.05227 https://

TeMFpy: a Python library for converting fermionic mean-field states into tensor networks
We introduce TeMFpy, a Python library for converting fermionic mean-field states to finite or infinite matrix product state (MPS) form. TeMFpy includes new, efficient, and easy-to-understand algorithms for both Slater determinants and Pfaffian states. Together with Gutzwiller projection, these also allow the user to build variational wave functions for various strongly correlated electron systems, such as quantum spin liquids. We present all implemented algorithms in detail and describe how the…

Quantum Critical Collapse Abhors a Naked Singularity
Marija Toma\v{s}evi\'c, Chih-Hung Wu
https://arxiv.org/abs/2509.03587 https://arxiv.org/pdf/2509.0…

Quantum Critical Collapse Abhors a Naked Singularity
Classical critical collapse yields naked singularities from smooth initial data, challenging cosmic censorship and shaping the spectrum of primordial black holes. We show that one-loop vacuum polarization near the threshold alters this outcome. In analytically tractable Einstein-scalar critical spacetimes, regularity uniquely selects a Boulware-like state whose stress tensor supplies a universal quantum growing mode. Its backreaction competes with the classical unstable mode, producing a shift …

Geometric quantum encoding of a turbulent field
Zhaoyuan Meng, Yue Yang
https://arxiv.org/abs/2508.05346 https://arxiv.org/pdf/2508.05346

Geometric quantum encoding of a turbulent field
The chaotic structure of multiscale systems presents a formidable challenge to their quantum encoding. We propose a three-stage hyperspherical encoding method for turbulent fields. This method comprises a symmetry-preserving perturbation of the ground state, a measurement-specific convolution, and a final deconvolution of observables. The latter two stages employ the Hopf fibration to map quantum observables onto vortex tubes, the building blocks of fluid turbulence. Using 27 qubits, we generat…

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 non-Gaussian high Fock states of light pulses and their superpositions
G. P. Teja, Chandan Kumar, Luk\'a\v{s} Lachman, Radim Filip
https://arxiv.org/abs/2509.04891 h…

Quantum non-Gaussian high Fock states of light pulses and their superpositions
The generation of high Fock states of light pulses and their superpositions with provable quantum non-Gaussian features is still very challenging, although the power of conditional methods to herald the approximate state from the available Gaussian states is growing. The atom-light interaction in the high-Q cavity has been considered a viable alternative to the heralded Fock states of the light pulses from nonlinear optics limited to three-photon Fock states for the last decade. Here, by optimi…

Laser-enhanced quantum sensing boosts sensitivity and dynamic range
Florian Schall, Lukas Lindner, Yves Rottstaedt, Marcel Rattunde, Florentin Reiter, R\"udiger Quay, Roman Bek, Alexander M. Zaitsev, Takeshi Ohshima, Andrew D. Greentree, Jan Jeske
https://arxiv.org/abs/2509.05204

Laser-enhanced quantum sensing boosts sensitivity and dynamic range
Magnetometers based on nitrogen-vacancy (NV) centers in diamond have emerged as the most important solid-state quantum sensors. However, ensembles are limited in optical contrast to typically a few percent and high-sensitivity variants usually possess only a few $\mathrmμ$T dynamic range. Here, we demonstrate a laser threshold magnetometry-based NV system that avoids these limitations. By integrating the NV centers into a laser cavity and showing magnetic-field-dependent shifts of the laser th…

Efficient Post-Selection for General Quantum LDPC Codes
Seok-Hyung Lee, Lucas English, Stephen D. Bartlett
https://arxiv.org/abs/2510.05795 https://arxiv.o…

Efficient Post-Selection for General Quantum LDPC Codes
Post-selection strategies that discard low-confidence computational results can significantly improve the effective fidelity of quantum error correction at the cost of reduced acceptance rates, which can be particularly useful for offline resource state generation. Prior work has primarily relied on the "logical gap" metric with the minimum-weight perfect matching decoder, but this approach faces fundamental limitations including computational overhead that scales exponentially with the number …

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…

Tensor Network Loop Cluster Expansions for Quantum Many-Body Problems
Johnnie Gray, Gunhee Park, Glen Evenbly, Nicola Pancotti, Garnet Kin-Lic Chan
https://arxiv.org/abs/2510.05647

Tensor Network Loop Cluster Expansions for Quantum Many-Body Problems
We analyze the tensor network loop cluster expansion, introduced in arXiv:2504.07344 as a systematic correction to belief propagation, in the context of general quantum many-body problems. We provide numerical examples of the accuracy and practical applicability of the approach for the computation of ground-state observables for high bond dimension tensor networks, in two- and three-dimensions, with open and periodic boundary conditions, and for spin and fermion problems.

Fold-transversal surface code cultivation
Kaavya Sahay, Pei-Kai Tsai, Kathleen Chang, Qile Su, Thomas B. Smith, Shraddha Singh, Shruti Puri
https://arxiv.org/abs/2509.05212 http…

Fold-transversal surface code cultivation
Magic state cultivation is a state-of-the-art protocol to prepare ultra-high fidelity non-Clifford resource states for universal quantum computation. It offers a significant reduction in spacetime overhead compared to traditional magic state distillation techniques. Cultivation protocols involve measuring a transversal logical Clifford operator on an initial small-distance code and then rapidly growing to a larger-distance code. In this work, we present a new cultivation scheme in which we meas…

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…

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…

Non-iid hypothesis testing: from classical to quantum
Giacomo De Palma, Marco Fanizza, Connor Mowry, Ryan O'Donnell
https://arxiv.org/abs/2510.06147 https://

Non-iid hypothesis testing: from classical to quantum
We study hypothesis testing (aka state certification) in the non-identically distributed setting. A recent work (Garg et al. 2023) considered the classical case, in which one is given (independent) samples from $T$ unknown probability distributions $p_1, \dots, p_T$ on $[d] = \{1, 2, \dots, d\}$, and one wishes to accept/reject the hypothesis that their average $p_{\mathrm{avg}}$ equals a known hypothesis distribution $q$. Garg et al. showed that if one has just $c = 2$ samples from each $p_i$,…

Testing Quantum Mechanics with Quantum Computers: Qubit Information Capacity
Tim Palmer
https://arxiv.org/abs/2510.02877 https://arxiv.org/pdf/2510.02877…

Testing Quantum Mechanics with Quantum Computers: Qubit Information Capacity
Motivated by John Wheeler's assertion that the continuum nature of Hilbert Space conceals the information-theoretic nature of the quantum wavefunction, a specific discretisation of complex Hilbert Space is proposed, leading to the notion of qubit information capacity $N_{\mathrm{max}}$: for any $N \ge N_{\mathrm{max}}$-qubit state, there is insufficient information in the $N$ qubits to allocate even one bit to each of the $2^{N+1}-2$ degrees of freedom demanded by complex Hilbert Space and henc…

Cultivating T states on the surface code with only two-qubit gates
Jahan Claes
https://arxiv.org/abs/2509.05232 https://arxiv.org/pdf/2509.05232

Cultivating T states on the surface code with only two-qubit gates
High-fidelity T magic states are a key requirement for fault-tolerant quantum computing in 2D. It has generally been assumed that preparing high-fidelity T states requires noisy injection of T states followed by lengthy distillation routines. This assumption has been recently challenged by the introduction of cultivation, in which careful state injection and postselection alone are used to prepare T states close to the fidelity required for quantum algorithms. Cultivation was originally propose…

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…

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…

Solving quantum-inspired dynamics on quantum and classical annealers
Philipp Hanussek, Jakub Paw{\l}owski, Zakaria Mzaouali, Bart{\l}omiej Gardas
https://arxiv.org/abs/2509.03952

Solving quantum-inspired dynamics on quantum and classical annealers
We propose a practical benchmarking suite inspired by physical dynamics to challenge both quantum and classical computers. Using a parallel in time encoding, we convert the real-time propagator of an $n$-qubit, possibly non-Hermitian, Hamiltonian into a quadratic-unconstrained binary optimisation (QUBO) problem. The resulting QUBO instances are executed on D-Wave quantum annealers as well as using two classical solvers, Simulated Annealing and VeloxQ, a state-of-the-art classical heuristic solv…

Replaced article(s) found for quant-ph. https://arxiv.org/list/quant-ph/new
[2/3]:
- Composable framework for device-independent state certification
Rutvij Bhavsar, Lewis Wooltorton, Joonwoo Bae

Polarization-Controlled Dual-State Distribution of Bell and N00N Entanglement Over a Metro-Scale Commercial Quantum Network
Kazi Reaz, Md Mehdi Hassan, Jacob E. Humberd, Matthew L. Boone, Angel Fraire Estrada, Rick Mukherjee, H. R. Sadeghpour, Girish S. Agarwal, George Siopsis, Tian Li
https://arxiv.org/abs/2509.03701

Polarization-Controlled Dual-State Distribution of Bell and N00N Entanglement Over a Metro-Scale Commercial Quantum Network
We report the first demonstration of multiphoton, dual state entanglement distribution over a metropolitan scale commercial fiber network, implemented on the EPB Bohr IV quantum network in Chattanooga, TN, using an all fiber optic experimental platform. Employing a spatially degenerate, continuous wave type II SPDC biphoton source and fully fiber coupled linear optics, we generated a 4 photon entangled state. Through polarization projective measurements on two locally retained photons, we then …

Modified logarithmic Sobolev inequalities for CSS codes
Sebastian Stengele, \'Angela Capel, Li Gao, Angelo Lucia, David P\'erez-Garc\'ia, Antonio P\'erez-Hern\'andez, Cambyse Rouz\'e, Simone Warzel
https://arxiv.org/abs/2510.03090

Modified logarithmic Sobolev inequalities for CSS codes
We consider the class of Davies quantum semigroups modelling thermalization for translation-invariant Calderbank-Shor-Steane (CSS) codes in D dimensions. We prove that conditions of Dobrushin-Shlosman-type on the quantum Gibbs state imply a modified logarithmic Sobolev inequality with a constant that is uniform in the system's size. This is accomplished by generalizing parts of the classical results on thermalization by Stroock, Zegarlinski, Martinelli, and Olivieri to the CSS quantum setting. …

Efficient quantum state tomography with Chebyshev polynomials
Hao Su, Shiying Xiong, Yue Yang
https://arxiv.org/abs/2509.02112 https://arxiv.org/pdf/2509.0…

Efficient quantum state tomography with Chebyshev polynomials
Quantum computing shows promise for addressing computationally intensive problems but is constrained by the exponential resource requirements of general quantum state tomography (QST), which fully characterizes quantum states through parameter estimation. We introduce the QST with Chebyshev polynomials, an approximate tomography method for pure quantum states encoding complex-valued functions. This method reformulates tomography as the estimation of Chebyshev expansion coefficients, expressed a…

Product-State Manifolds for M Quantum Systems with N Levels using the Fano form and the Induced Euclidean Metric
Fotios D. Oikonomou
https://arxiv.org/abs/2509.02891 https://

Product-State Manifolds for M Quantum Systems with N Levels using the Fano form and the Induced Euclidean Metric
In quantum mechanics separable states can be characterized as convex combinations of product states whereas non-separable states exhibit entanglement. Quantum entanglement has played a pivotal role in both theoretical investigations and practical applications within quantum information science. In this study, we explore the connection between product states and geometric structures, specifically manifolds and their associated geometric properties such as the first fundamental form (metric). We …

Quantum theory phase space foundations
Milo\v{s} D. Davidovi\'c, Ljubica D. Davidovi\'c, Milena D. Davidovi\'c
https://arxiv.org/abs/2509.03237 https://

Quantum theory phase space foundations
We give a review of concepts related to connection of classical and quantum theories, from the phase space perspective. Quantum theory is described by non-commutative operators of coordinates and momenta, results in values having a certain probability, hence resembling the classical statistical theory in which coordinates and momenta are well measurable quantities. The search is for the classical object best describing the quantum state, while the physical observables of the quantum theories ar…

Quantum Circuit Design using Complex valued Neural Network in Stiefel Manifold
Sayan Manna, Mahesh Mohan M R
https://arxiv.org/abs/2509.02374 https://arxiv…

Quantum Circuit Design using Complex valued Neural Network in Stiefel Manifold
Quantum algorithms operate on quantum states through unitary transformations in high dimensional complex Hilbert space. In this work, we propose a machine learning approach to create the quantum circuit using a single-layer complex-valued neural network. The input and ouput quantum states are provided to the network, which is trained to approximate the output state of a given quantum algorithm. To ensure that the fundamental property of unitarity is preserved throughout the training process, we…

Perfect Quantum State Revivals: Designing Arbitrary Potentials with Specified Energy Levels
Aaron Danner, Tom\'a\v{s} Tyc
https://arxiv.org/abs/2510.00874 https://

Perfect Quantum State Revivals: Designing Arbitrary Potentials with Specified Energy Levels
It is known that there exist a limited number of analytic potentials with the unusual property that any bound quantum state therein will be periodic in time. This is known as a perfect quantum state revival. Examples of such potentials are the infinite well, quantum harmonic oscillator and the Pöschl-Teller potentials; here, we present a general method of designing such potentials. A key requirement is that their energy eigenvalues have integer spacings (up to a prefactor). We first analyze th…

Quantum Resource Theory of Deficiency and Operational Applications in Subchannel Discrimination
Sunho Kim, Chunhe Xiong, Junde Wu
https://arxiv.org/abs/2509.03043 https://

Quantum Resource Theory of Deficiency and Operational Applications in Subchannel Discrimination
A central challenge in quantum resource theory is to provide operational meaning to quantum resources that offer distinct advantages over the convex set of resource-free states in specific physical tasks. We propose a novel framework to define the resource deficiency of a given state relative to the set of maximal resource states in physical tasks. The proposed geometric measure satisfies this framework's conditions for both quantum coherence and entanglement, and it precisely quantifies the mi…

Boundary Time Crystals: Beyond Mean-Field Theory
Zeping Liu, Yaotian Li, Zhaoyu Fei, Xiaoguang Wang
https://arxiv.org/abs/2510.03028 https://arxiv.org/pdf/…

Boundary Time Crystals: Beyond Mean-Field Theory
Boundary time crystals are a class of exotic dissipative quantum phases that spontaneously break continuous time-translation symmetry in the thermodynamic limit of open quantum systems. In finite-size systems, the long-time evolution of boundary time crystals exhibits decaying oscillations that cannot be captured by widely used mean-field theory. To address this issue, we develop an effective approach called the stroboscopic rotating wave approximation, which provides a well approximate state f…

Understanding Quantum Imaginary Time Evolution and its Variational form
Angl\'es-Castillo Andreu, Ion Luca, Pandit Tanmoy, Gomez-Lurbe Rafael, Mart\'inez Rodrigo, Garcia-March Miguel Angel
https://arxiv.org/abs/2510.02015

Understanding Quantum Imaginary Time Evolution and its Variational form
Many computationally hard problems can be encoded in quantum Hamiltonians. The solution to these problems is given by the ground states of these Hamiltonians. A state-of-the-art algorithm for finding the ground state of a Hamiltonian is the so-called Quantum Imaginary Time Evolution (QITE) which approximates imaginary time evolution by a unitary evolution that can be implemented in quantum hardware. In this paper, we review the original algorithm together with a comprehensive computer program, …

Evidence of Compact Wavefunctions from Quantum-Selected Configuration Interaction
Tim Weaving, Angus Mingare, Alexis Ralli, Peter V. Coveney
https://arxiv.org/abs/2509.02525 htt…

Evidence of Compact Wavefunctions from Quantum-Selected Configuration Interaction
A recent direction in quantum computing for molecular electronic structure sees the use of quantum devices as configuration sampling machines integrated within high-performance computing (HPC) platforms. This appeals to the strengths of both the quantum and classical hardware; where state-sampling is classically hard, the quantum computer can provide computational advantage in the selection of high quality configuration subspaces, while the final molecular energies are evaluated by solving an i…

Real-time adaptive quantum error correction by model-free multi-agent learning
Manuel Guatto, Francesco Preti, Michael Schilling, Tommaso Calarco, Francisco Andr\'es C\'ardenas-L\'opez, Felix Motzoi
https://arxiv.org/abs/2509.03974

Real-time adaptive quantum error correction by model-free multi-agent learning
Can we build efficient Quantum Error Correction (QEC) that adapts on the fly to time-varying noise? In this work we say yes, and show how. We present a two level framework based on Reinforcement Learning (RL) that learns to correct even non-stationary errors from scratch. At the first level we take advantage of model-free Multi-Agent RL (MARL) to automatically discover full QEC cycle -- logical state encoding, stabilizer measurements, and recovery -- without any prior system knowledge, relying …

Visualizing Quantum Circuits: State Vector Difference Highlighting and the Half-Matrix
Michael J. McGuffin, Jean-Marc Robert
https://arxiv.org/abs/2510.00895 https://

Visualizing Quantum Circuits: State Vector Difference Highlighting and the Half-Matrix
Existing graphical user interfaces for circuit simulators often show small visual summaries of the reduced state of each qubit, showing the probability, phase, purity, and/or Bloch sphere coordinates associated with each qubit. These necessarily provide an incomplete picture of the quantum state of the qubits, and can sometimes be confusing for students or newcomers to quantum computing. We contribute two novel visual approaches to provide more complete information about small circuits. First, …

A simple method for seniority-zero quantum state preparation
Michal Krompiec, Josh J. M. Kirsopp, Antonio M\'arquez Romero, Vicente Perez Soloviev
https://arxiv.org/abs/2508.21679

A simple method for seniority-zero quantum state preparation
Quantum Phase Estimation (QPE), the quantum algorithm for estimating eigenvalues of a given Hermitian matrix and preparing its eigenvectors, is considered the most promising approach to finding the ground states and their energies of electronic systems using a quantum computer. It requires, however, to be warm--started from an initial state with sufficiently high overlap with the ground state. For strongly-correlated states, where QPE is expected to have advantage over classical methods, prepar…

HCQA: Hybrid Classical-Quantum Agent for Generating Optimal Quantum Sensor Circuits
Ahmad Alomari, Sathish A. P. Kumar
https://arxiv.org/abs/2508.21246 https://

HCQA: Hybrid Classical-Quantum Agent for Generating Optimal Quantum Sensor Circuits
This study proposes an HCQA for designing optimal Quantum Sensor Circuits (QSCs) to address complex quantum physics problems. The HCQA integrates computational intelligence techniques by leveraging a Deep Q-Network (DQN) for learning and policy optimization, enhanced by a quantum-based action selection mechanism based on the Q-values. A quantum circuit encodes the agent current state using Ry gates, and then creates a superposition of possible actions. Measurement of the circuit results in prob…

Quantum Dynamics with Time-Dependent Neural Quantum States
Alejandro Romero-Ros, Javier Rozal\'en Sarmiento, Arnau Rios
https://arxiv.org/abs/2509.24865 https://

Quantum Dynamics with Time-Dependent Neural Quantum States
We present proof-of-principle time-dependent neural quantum state (NQS) simulations to illustrate the ability of this approach to effectively capture key aspects of quantum dynamics in the continuum. NQS leverage the parameterization of the wave function with neural-network architectures. Here, we put NQS to the test by solving the quantum harmonic oscillator. We obtain the ground state and perform coherent state and breathing mode dynamics. Our results are benchmarked against analytical soluti…

Demonstration of quantum error detection in a silicon quantum processor
Chunhui Zhang, Chunhui Li, Zhen Tian, Yan Jiang, Feng Xu, Shihang Zhang, Hao Wang, Yu-Ning Zhang, Xuesong Bai, Baolong Zhao, Yi-Fei Zhang, Huan Shu, Jiaze Liu, Kunrong Wu, Chao Huang, Keji Shi, Mingchao Duan, Tao Xin, Peihao Huang, Tianluo Pan, Song Liu, Guanyong Wang, Guangchong Hu, Yu He, Dapeng Yu

Demonstration of quantum error detection in a silicon quantum processor
Quantum error detection is essential in realizing large-scale universal quantum computation, especially for quantum error correction (QEC). However, key elements for FTQC have yet to be realized in silicon qubits. Here, we demonstrate quantum error detection on a donor-based silicon quantum processor comprising four-nuclear spin qubits and one electron spin as an auxiliary qubit. The entanglement capability of this system is validated through the establishment of two-qubit Bell state entangleme…

Quantum speed-up for solving the one-dimensional Hubbard model using quantum annealing
Kunal Vyas, Fengping Jin, Hans De Raedt, Kristel Michielsen
https://arxiv.org/abs/2510.02141

Quantum speed-up for solving the one-dimensional Hubbard model using quantum annealing
The Hubbard model has occupied the minds of condensed matter physicists for most part of the last century. This model provides insight into a range of phenomena in correlated electron systems. We wish to examine the paradigm of quantum algorithms for solving such many-body problems. The focus of our current work is on the one-dimensional model which is integrable, meaning that there exist analytical results for determining its ground state. In particular, we demonstrate how to perform a gate-ba…

Quantum Sequential Universal Hypothesis Testing
Matteo Zecchin, Osvaldo Simeone, Aaditya Ramdas
https://arxiv.org/abs/2508.21594 https://arxiv.org/pdf/2508…

Quantum Sequential Universal Hypothesis Testing
Quantum hypothesis testing (QHT) concerns the statistical inference of unknown quantum states. In the general setting of composite hypotheses, the goal of QHT is to determine whether an unknown quantum state belongs to one or another of two classes of states based on the measurement of a number of copies of the state. Prior art on QHT with composite hypotheses focused on a fixed-copy two-step protocol, with state estimation followed by an optimized joint measurement. However, this fixed-copy ap…

A Review of Software for Designing and Operating Quantum Networks
Robert J. Hayek, Joaquin Chung, Rajkumar Kettimuthu
https://arxiv.org/abs/2510.00203 https://

A Review of Software for Designing and Operating Quantum Networks
Quantum network protocol development is crucial to realizing a production-grade network that can support distributed sensing, secure communication, and utility-scale quantum computation. However, the transition from laboratory demonstration to deployable networks requires software implementations of architectures and protocols tailored to the unique constraints of quantum systems. This paper reviews the current state of software implementations for quantum networks, organized around the three-p…

Optimizing sparse quantum state preparation with measurement and feedforward
Yao-Cheng Lu, Han-Hsuan Lin
https://arxiv.org/abs/2508.21346 https://arxiv.org…

Optimizing sparse quantum state preparation with measurement and feedforward
Quantum state preparation (QSP) is a key component in many quantum algorithms. In particular, the problem of sparse QSP (SQSP) $\unicode{x2013}$ the task of preparing the states with only a small number of non-zero amplitudes $\unicode{x2013}$ has garnered significant attention in recent years. In this work, we focus on reducing the circuit depth of SQSP with limited number of ancilla qubits. We present two SQSP algorithms: one with depth $O(n\log d)$, and another that reduces depth to $O(n)$. …

Universal Analytic Solution for the Quantum Transport of Structured Matter-Waves in Magnetic Optics
N. V. Filina, S. S. Baturin
https://arxiv.org/abs/2509.03264 https://

Universal Analytic Solution for the Quantum Transport of Structured Matter-Waves in Magnetic Optics
We present a closed-form analytic solution for the propagation of an arbitrary charged scalar state in a non-uniform magnetic field. The dynamics are governed by classical beam optics parameters (Courant-Snyder parameters), the Twiss functions, and phase advance, revealing a direct map between quantum evolution and its classical counterpart. The solution decomposes into three components, exhibiting a complex rotation dependent on the sign of the orbital angular momentum (OAM) projection, alongs…

1D Cluster State Generation On Superconducting Hardware
Rahul Dev Sharma, Md Sakibul Islam
https://arxiv.org/abs/2508.21798 https://arxiv.org/pdf/2508.2179…

1D Cluster State Generation On Superconducting Hardware
Measurement-based Quantum Computation(MBQC) utilize entanglement as resource for performing quantum computation. Generating cluster state using entanglement as resource is a key bottleneck for the adoption of MBQC. To generate cluster state with charge-qubit arrrays, we provide analytical derivations and numerical validations for 4-qubit cluster state. We compare our fidelities under ideal (noise-free) Hamiltonian evolution and due to effect of decoherence. We show incorporating energy relaxati…

Limitations of strong coupling in non-Markovian quantum thermometry
Qing-Shou Tan, Yang Liu, Xulin Liu, Hao Chen, Xing Xiao, Wei Wu
https://arxiv.org/abs/2510.01596 https://

Limitations of strong coupling in non-Markovian quantum thermometry
We investigate quantum thermometry using a single-qubit probe embedded in a non-Markovian environment, employing the numerically exact hierarchical equations of motion (HEOM) to overcome the limitations of Born-Markov approximations. Through a systematic analysis of the dynamical and steady-state behavior of the quantum signal-to-noise ratio (QSNR) for temperature estimation, we identify several key findings that challenge the conventional expectation that strong coupling necessarily enhances t…

From Bell Products to GHZ: Quantum Memories via Emergent Hamiltonians
Anubhab Sur, Qiujiang Guo, Rubem Mondaini
https://arxiv.org/abs/2510.01117 https://ar…

From Bell Products to GHZ: Quantum Memories via Emergent Hamiltonians
With the advent of exquisite quantum emulators, storing highly entangled many-body states becomes essential. While entanglement typically builds over time when evolving a quantum system initialized in a product state, freezing that information at any given instant requires quenching to a Hamiltonian with the time-evolved state as an eigenstate, a concept we realize via an Emergent Hamiltonian framework. While the Emergent Hamiltonian is generically non-local and may lack a closed form, we show …

Exponentially Enhanced Tripartite Coupling in Quantum Nonlinear Magnonics
Xue-Chun Chen, Zi-Jie Wang, Sheng-Bo Zheng, Jiaojiao Chen, Wei Xiong
https://arxiv.org/abs/2509.01884 h…

Exponentially Enhanced Tripartite Coupling in Quantum Nonlinear Magnonics
Strong and controllable tripartite interactions play a pivotal role in quantum information and nonlinear quantum optics, yet challenging to realize. In this work, we propose a hybrid system consisting of a nitrogen-vacancy (NV) center coupled to Kerr magnons (magnons with Kerr nonlinearity) in two yttrium-iron-garnet spheres. By adiabatically eliminating the ground state of the NV qutrit in the dispersive regime, an effective tripartite interaction among magnons and an NV qubit encoded in its e…

Indefinite causal order in cavity quantum electrodynamics
Lorenzo M. Procopio, L. O. Casta\~nos-Cervantes, Tim J. Bartley
https://arxiv.org/abs/2509.02209 https://

Indefinite causal order in cavity quantum electrodynamics
Indefinite causal order (ICO) has the potential to be a new resource for quantum information processing. In most of its experiments, ICO has been investigated in a photonic platform. Here we investigate ICO in a cavity quantum electrodynamics (cQED) system composed of two cavities. Our results show that ICO can create entanglement between two distant cavity fields that never interact directly, and for the case of two cavity fields in the vacuum state, ICO presents an advantage over the fixed-or…

Efficient and optimal quantum state discrimination via quantum belief propagation
Christophe Piveteau, Joseph M. Renes
https://arxiv.org/abs/2509.19441 https://

Efficient and optimal quantum state discrimination via quantum belief propagation
We present an efficient quantum algorithm for a structured state discrimination problem we call the subspace decoding task. Building on this, we show that the algorithm enables efficient and optimal decoding of certain families of structured classical linear codes transmitted over binary-input classical-quantum pure-state channels. Such decoders can substantially enhance the performance of quantum algorithms based on Regev's reduction, such as decoded quantum interferometry. In particular, we o…

Tracking Quantum State Collapse/Decoherence in Real Time via a Superposition Trap
Hardeep Singh, Tim Kovachy
https://arxiv.org/abs/2509.23053 https://arxiv…

Tracking Quantum State Collapse/Decoherence in Real Time via a Superposition Trap
We propose a novel method for probing quantum state collapse and decoherence in real time using a mechanism we term the superposition trap. This approach exploits the continuity equation in quantum mechanics to engineer a configuration that spatially confines only coherent superpositions, while allowing decohered or collapsed states to escape. By monitoring this leakage, the dynamics of collapse processes-whether environmentally induced or intrinsic to objective collapse models-can be experimen…

Temperature-induced measurement sensitivity enhancement via imaginary weak values
Lorena Ballesteros Ferraz, Alexandre Matzkin, Alok Kumar Pan
https://arxiv.org/abs/2509.04048 h…

Temperature-induced measurement sensitivity enhancement via imaginary weak values
We investigate the potential of weak measurement and post-selection to enhance measurement sensitivity when the initial probe state is mixed. In our framework, the mixedness of the probe's density operator is controlled by temperature. We focus on two key quantities: the signal-to-noise ratio and the quantum Fisher information of the final probe state, evaluated after post-selection is applied on the system. Our analysis employs a rigorous, all-order coupling treatment of measurement, demonstra…

Feature- and process-based optimal control of quantum dynamics
M. Farnia, V. Rezvani, A. T. Rezakhani
https://arxiv.org/abs/2509.22401 https://arxiv.org/pd…

Feature- and process-based optimal control of quantum dynamics
Preparing desired quantum states and quantum operations (processes) is essential for numerous tasks in quantum computation. Several approaches have been developed for optimal control of quantum states, whereas optimal strategies for preparation of a given quantum process have remained fairly less explored. For some applications, rather than a specific desired state or process, it may suffice to obtain states or processes with specific desired features such as (high) coherence or purity. In such…

Toward Quantum-Enabled Biomarker Discovery: An Outlook from Q4Bio
Dhirpal Shah, Mariesa Teo, Ryan A. Robinett, Sophia Madejski, Zachary Morrell, Siddhi Ramesh, Colin Campbell, Bharath Thotakura, Victory Omole, Ben Hall, Aram W. Harrow, Teague Tomesh, Alexander T. Pearson, Frederic T. Chong, Samantha J. Riesenfeld
https://arxiv.org/abs/2509…

Toward Quantum-Enabled Biomarker Discovery: An Outlook from Q4Bio
We present a case study and forward-looking perspective on co-design for hybrid quantum-classical algorithms, centered on the goal of empirical quantum advantage (EQA), which we define as a measurable performance gain using quantum hardware over state-of-the-art classical methods on the same task. Because classical algorithms continue to improve, the EQA crossover point is a moving target; nevertheless, we argue that a persistent advantage is possible for our application class even if the cross…

Symmetric quantum walks on Hamming graphs and their limit distributions
Robert C. Griffiths, Shuhei Mano
https://arxiv.org/abs/2509.26243 https://arxiv.org…

Symmetric quantum walks on Hamming graphs and their limit distributions
We study a class of symmetric quantum walks on Hamming graphs, where the distance between vertices specifies the transition probability. A special model is the simple quantum walk on the hypercube, which has been discussed in the literature. Eigenvalues of the unitary operator of the quantum walks are zeros of certain self-reciprocal polynomials. We obtain a spectral representation of the wave vector, where our systematic treatment relies on the coin space isomorphic to the state space and the …

Quantum Tomography of Suspended Carbon Nanotubes
Jialiang Chang, Nicholas Pietrzak, Cristian Staii
https://arxiv.org/abs/2509.01858 https://arxiv.org/pdf/2…

Quantum Tomography of Suspended Carbon Nanotubes
We present an all-mechanical protocol for coherent control and full quantum-state reconstruction of the fundamental flexural mode of a suspended carbon nanotube (CNT). Calibrated impulses from a nearby atomic force microscope (AFM) tip serve a dual role: they implement mechanical pi/2 rotations for Ramsey interferometry and realize phase-space displacements for Wigner function tomography via displaced-parity sampling. The same actuator thus unifies control and tomography while avoiding optical …

Nonclassical phonon pair
Yu Wang, Zhen Shen, Mai Zhang, Zhi-Peng Shi, Hong-Yi Kuang, Shuai Wan, Fang-Wen Sun, Guang-Can Guo, Chun-Hua Dong
https://arxiv.org/abs/2509.24429 https…

Nonclassical phonon pair
Quantum-correlated photon pairs are crucial resources for modern quantum information science. Similarly, the reliable generation of nonclassical phonon pairs is vital for advancing engineerable solid-state quantum devices and hybrid quantum networks based on phonons. Here, we present a novel approach to generate quantum-correlated phonon pairs in a suspended silicon microstructure initialized in its motional ground state. By simultaneously implementing red- and blue-detuned laser pulses, equiva…

Replaced article(s) found for quant-ph. https://arxiv.org/list/quant-ph/new
[1/2]:
- Linear Gaussian Quantum State Smoothing: Understanding the optimal unravelings for Alice to estim...
Kiarn T. Laverick, Areeya Chantasri, Howard M. Wiseman

Quantum Measurement Trees, II: Quantum Observables as Ortho-Measurable Functions and Density Matrices as Ortho-Probability Measures
Peter J. Hammond
https://arxiv.org/abs/2509.22617

Quantum Measurement Trees, II: Quantum Observables as Ortho-Measurable Functions and Density Matrices as Ortho-Probability Measures
Given a quantum state in the finite-dimensional Hilbert space $ \C^n $, the range of possible values of a quantum observable is usually identified with the discrete spectrum of eigenvalues of a corresponding Hermitian matrix. Here any such observable is identified with: (i) an ``ortho-measurable'' function defined on the Boolean ``ortho-algebra'' generated by the eigenspaces that form an orthogonal decomposition of $ \C^n $; (ii) a ``numerically identified'' orthogonal decomposition of $ \C^n $…