Tootfinder

This https://arxiv.org/abs/2402.04705 has been replaced.
link: https://scholar.google.com/scholar?q=a

Decoherence rate in random Lindblad dynamics
Open quantum systems undergo decoherence, which is responsible for the transition from quantum to classical behavior. The time scale in which decoherence takes place can be analyzed using upper limits to its rate. We examine the dynamics of open chaotic quantum systems governed by random Lindblad operators sourced from Gaussian and Ginibre ensembles with Wigner-Dyson symmetry classes. In these systems, the ensemble-averaged purity decays monotonically as a function of time. This decay is govern…

This https://arxiv.org/abs/2403.03106 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Understanding gravitationally induced decoherence parameters in neutrino oscillations using a microscopic quantum mechanical model
In this work, a microscopic quantum mechanical model for gravitationally induced decoherence introduced by Blencowe and Xu is investigated in the context of neutrino oscillations. The focus is on the comparison with existing phenomenological models and the physical interpretation of the decoherence parameters in such models. The results show that for neutrino oscillations in vacuum gravitationally induced decoherence can be matched with phenomenological models with decoherence parameters of the…

This https://arxiv.org/abs/2303.04829 has been replaced.
link: https://scholar.google.com/scholar?q=a

Initial value formulation of a quantum damped harmonic oscillator
The in-in formalism and its influence functional generalization are widely used to describe the out-of-equilibrium dynamics of unitary and open quantum systems, respectively. In this paper, we build on these techniques to develop an effective theory of a quantum damped harmonic oscillator and use it to study initial state-dependence, decoherence, and thermalization. We first consider a Gaussian initial state and quadratic influence functional and obtain general equations for the Green's functio…

Searching for Decoherence from Quantum Gravity at the #IceCube South Pole Neutrino Observatory: https://arxiv.org/abs/2308.00105 -> IceCube search for neutrino decoherence from quantum gravity: https://icecube.wisc.edu/news/research/2024/03/icecube-search-for-neutrino-decoherence-from-quantum-gravity/

This https://arxiv.org/abs/2308.14107 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Unravelling Metastable Markovian Open Quantum Systems
We analyse the dynamics of metastable Markovian open quantum systems by unravelling their average dynamics into stochastic trajectories. We use quantum reset processes as examples to illustrate metastable phenomenology, including a simple three-state model whose metastability is of classical type, and a two-qubit model that features a metastable decoherence free subspace. In the three-state model, the trajectories exhibit classical metastable phenomenology: fast relaxation into distinct phases …

Comparing the decoherence effects due to black holes versus ordinary matter
Anna Biggs, Juan Maldacena
https://arxiv.org/abs/2405.02227 https://

Comparing the decoherence effects due to black holes versus ordinary matter
Recently a certain thought experiment was discussed which involves the decoherence of a quantum system due to a black hole. Here we show how this phenomenon is consistent with standard ideas about quantum black holes. In other words, modeling the black hole as a quantum system at finite temperature one obtains the same answer. We demonstrate this by analyzing the problem in terms of an effective theory that can apply both for the black hole case and for an ordinary matter system, showing that t…

This https://arxiv.org/abs/2404.02016 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Brownian Particles and Matter Waves
In view of the remarkable progress in micro-rheology to monitor the random motion of Brownian particles with size as small as few nanometers, in association that de Broglie matter waves have been experimentally observed for large molecules of comparable nanometer size; we examine whether Brownian particles can manifest a particle-wave duality without employing a priori arguments from quantum decoherence. First, we examine the case where Brownian particles are immersed in a memoryless viscous fl…

This https://arxiv.org/abs/2402.02470 has been replaced.
link: https://scholar.google.com/scholar?q=a

Probing quantum decoherence at Belle II and LHCb
With the advent of Belle II and the LHCb upgrade, the precision measurements of various B-Physics observables are on cards. This holds significant potential for delving into physics beyond the standard model of electroweak interactions. These measurements can also serve as means to establish limits on phenomena occurring at much finer length scales, such as quantum decoherence, which may arise due to potential discreteness in space-time or non-trivial topological effects. In this work, we set u…

Measurement Schemes in AQFT, Contextuality and the Wigner's Friend Gedankenexperiment
Felipe Dilho Alves
https://arxiv.org/abs/2402.19235 https://

Measurement Schemes in AQFT, Contextuality and the Wigner's Friend Gedankenexperiment
Measurements have historically presented a problem for the consistent description of quantum theories, be it in non-relativistic quantum mechanics or in quantum field theory. Drawing on a recent surge of interest in the description of measurements in Algebraic Quantum Field theory, it was decided that this dissertation would be focused on trying to close the gap between the description of measurements proposed by K. Hepp in the 70's, considering decoherence of states in quasilocal algebras and …

Decoherence in Neutrino Oscillation at the ESSnuSB Experiment
ESSnuSB, :, J. Aguilar, M. Anastasopoulos, E. Baussan, A. K. Bhattacharyya, A. Bignami, M. Blennow, M. Bogomilov, B. Bolling, E. Bouquerel, F. Bramati, A. Branca, G. Brunetti, I. Bustinduy, C. J. Carlile, J. Cederkall, T. W. Choi, S. Choubey, P. Christiansen, M. Collins, E. Cristaldo Morales, P. Cupia{\l}, H. Danared, D. Dancila, J. P. A. M. de Andr\'e, M. Dracos, I. Efthymiopoulos, T. Ekel\"of, M. Eshraqi, G. Fano…

Decoherence in Neutrino Oscillation at the ESSnuSB Experiment
Neutrino oscillation experiments provide a unique window in exploring several new physics scenarios beyond the standard three flavour. One such scenario is quantum decoherence in neutrino oscillation which tends to destroy the interference pattern of neutrinos reaching the far detector from the source. In this work, we study the decoherence in neutrino oscillation in the context of the ESSnuSB experiment. We consider the energy-independent decoherence parameter and derive the analytical express…

This https://arxiv.org/abs/2307.13443 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Decoherence and entropy generation at one loop in the inflationary de Sitter spacetime for Yukawa interaction
The decoherence mechanism is believed to be possibly connected to the quantum to classical transition of the primordial cosmological perturbations in the early universe. In this paper, we extend our previous analysis on decoherence in a fermion and scalar quantum field theory coupled via the Yukawa interaction in the Minkowski spacetime, to the inflationary de Sitter background. We treat the scalar field as the system and the fermions as the environment, and both the fields are taken to be mass…

This https://arxiv.org/abs/2311.14020 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Quantum Simulation of Bound-State-Enhanced Quantum Metrology
Quantum metrology explores quantum effects to improve the measurement accuracy of some physical quantities beyond the classical limit. However, due to the interaction between the system and the environment, the decoherence can significantly reduce the accuracy of the measurement. Many methods have been proposed to restore the accuracy of the measurement in the long-time limit. Recently, it has been found that the bound state can assist the error-free measurement and recover the $t^{-1}$ scaling…

Two Quantum Paradigms, but Still No Signal
Samuel Epstein
https://arxiv.org/abs/2402.13049 https://arxiv.org/pdf/2402.13049

Two Quantum Paradigms, but Still No Signal
An overwhelming majority of quantum (pure and mixed) states, when undertaking a POVM measurement, will result in a classical probability with no algorithmic information. Thus most quantum states produce white noise when measured. Furthermore most non-pointer states, when undergoing the decoherence process, will produce white noise. These results can be seen as consequences of the vastness of Hilbert spaces.

This https://arxiv.org/abs/2311.12619 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Two-dimensional symmetry-protected topological phases and transitions in open quantum systems
We investigate the influence of local decoherence on a symmetry-protected topological (SPT) phase of the two-dimensional (2D) cluster state. Mapping the 2D cluster state under decoherence to a classical spin model, we show a topological phase transition of a $\mathbb{Z}_2^{(0)}\times\mathbb{Z}_{2}^{(1)}$ SPT phase into the trivial phase occurring at a finite decoherence strength. To characterize the phase transition, we employ three distinct diagnostic methods, namely, the relative entropy betw…

Bias Control and Linearization of the Transfer Function of Electro-optic and Acousto-optic Modulators
Clemens Neum\"uller, Frank Obernosterer, Raimund Meyer, Robert Koch, Gerd Kilian
https://arxiv.org/abs/2403.10331

Bias Control and Linearization of the Transfer Function of Electro-optic and Acousto-optic Modulators
In several types of quantum computers light is one of the main tools to control both the position and the quantum state of the atoms used for computing. In practical systems laser light is applied to manipulate quantum states of qubits in the desired way. Beside physical effects like decoherence and quantum noise the precision of qubit manipulation has a significant impact on the achievable quantum computing error rate. One of the key optical components beside the laser is the optical modulator…

This https://arxiv.org/abs/2401.07690 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Encoding position by spins: Objectivity in the boson-spin model
We investigate quantum objectivity in the boson-spin model, where a central harmonic oscillator interacts with a thermal bath of spin-1/2 systems. We analyze how information about a continuous position variable can be encoded into discrete, finite-dimensional environments. More precisely, we study conditions under which the so-called Spectrum Broadcast Structures (SBS) can be formed in the model. These are multipartite quantum state structures, representing a mode-refined form of decoherence. W…

Decoherence by warm horizons
Jordan Wilson-Gerow, Annika Dugad, Yanbei Chen
https://arxiv.org/abs/2405.00804 https://arxiv.org/pdf/24…

Decoherence by warm horizons
Recently Danielson, Satishchandran, and Wald (DSW) have shown that quantum superpositions held outside of Killing horizons will decohere at a steady rate. This occurs because of the inevitable radiation of soft photons (gravitons), which imprint a electromagnetic (gravitational) ``which-path'' memory onto the horizon. Rather than appealing to this global description, an experimenter ought to also have a local description for the cause of decoherence. One might intuitively guess that this is jus…

This https://arxiv.org/abs/2403.03106 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Understanding gravitationally induced decoherence parameters in neutrino oscillations using a microscopic quantum mechanical model
In this work, a microscopic quantum mechanical model for gravitationally induced decoherence introduced by Blencowe and Xu is investigated in the context of neutrino oscillations. The focus is on the comparison with existing phenomenological models and the physical interpretation of the decoherence parameters in such models. The results show that for neutrino oscillations in vacuum gravitationally induced decoherence can be matched with phenomenological models with decoherence parameters of the…

This https://arxiv.org/abs/2403.09840 has been replaced.
initial toot: https://mastoxiv.page/@a…

Dark versus blocking states in electronic transport: a Lee-Yang zero analysis of full counting statistics
Electronic transport through nanostructures can be suppressed by coherent population trapping, in which quantum coherence leads to a dark state that decouples from the drain electrode. Finite transport, then, relies on decoherence of the dark state. An alternative scenario for reduced transport is weak coupling of a state, referred to as a blocking state, to the drain. This raises the question of whether and how these two scenarios can be distinguished in the transport features. For the example…

Exploring rare-earth Kitaev magnets by massive-scale computational analysis
Seong-Hoon Jang, Yukitoshi Motome
https://arxiv.org/abs/2402.18837 https://

Exploring rare-earth Kitaev magnets by massive-scale computational analysis
The Kitaev honeycomb model plays a pivotal role in the quest for quantum spin liquids, in which fractional quasiparticles would provide applications in decoherence-free topological quantum computing. The key ingredient is the bond-dependent Ising-type interactions, dubbed the Kitaev interactions, which require strong entanglement between spin and orbital degrees of freedom. This study investigates the identification and design of rare-earth materials displaying robust Kitaev interactions. We sc…

This https://arxiv.org/abs/2310.09880 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Decoherence is an echo of Anderson localization in open quantum systems
We study the time evolution of single-particle quantum states described by a Lindblad master equation with local terms. By means of a geometric resolvent equation derived for Lindblad generators, we establish a finite-volume-type criterion for the decay of the off-diagonal matrix elements in the position basis of the time-evolved or steady states. This criterion is shown to yield exponential decay for systems where the non-hermitian evolution is either gapped or strongly disordered. The gap exi…

This https://arxiv.org/abs/2402.01170 has been replaced.
link: https://scholar.google.com/scholar?q=a

Maxwell demon with anti-decoherence
Subsystems of a composite system in a pure state generally exist in mixed states and undergo changes with the overall state. This phenomenon arises from the coherence of the entire system and represents a crucial distinction between quantum and classical systems. Such a quantum property can enhance the work of an Otto heat engine, where two coupled qubits serve as the working substance, allowing situations in which negative work output initially occurred to now yield positive work. We utilize t…

This https://arxiv.org/abs/2309.07236 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Open Quantum System Approach to the Gravitational Decoherence of Spin-1/2 Particles
This paper investigates the decoherence effect resulting from the interaction of squeezed gravitational waves with a system of massive particles in spatial superposition. This paper investigates the decoherence effect resulting from the interaction of squeezed gravitational waves with a system of massive particles in spatial superposition. We first employ the open quantum system approach to obtain the established decoherence in a spatial superposition of massive objects induced by squeezed grav…

Observation of electronic coherence created at conical intersections and its decoherence in aqueous solution
Yi-Ping Chang, Tadas Balciunas, Zhong Yin, Marin Sapunar, Bruno N. C. Tenorio, Alexander C. Paul, Shota Tsuru, Henrik Koch, Jean Pierre Wolf, Sonia Coriani, Hans Jakob W\"orner
https://arxiv.org/abs/2402.10508…

Observation of electronic coherence created at conical intersections and its decoherence in aqueous solution
Electronic quantum coherence is a prerequisite for charge migration in molecules and emerging molecular quantum technologies. It also underlies new forms of spectroscopy and can enhance molecular function. Whether conical intersections can create electronic coherence and for how long electronic coherence can survive in aqueous environments has remained elusive and controversial, respectively. Here, we use X-ray spectroscopy to realize a breakthrough on both of these topics. We find that electro…

This https://arxiv.org/abs/2306.14778 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

Constraints on quantum spacetime-induced decoherence from neutrino oscillations
We investigate the implications of decoherence induced by quantum spacetime properties on neutrino oscillation phenomena. We develop a general formalism where the evolution of neutrinos is governed by a Lindblad-type equation and we compute the oscillation damping factor for various models that have been proposed in the literature. Furthermore, we discuss the sensitivity to these effects of different types of neutrino oscillation experiments, encompassing astrophysical, atmospheric, solar, and …

This https://arxiv.org/abs/2312.00376 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Dynamics of a quantum system interacting with white non-Gaussian baths: Poisson noise master equation
Quantum systems are unavoidably open to their surrounding degrees of freedom. The theory of open quantum systems is thus crucial to understanding the fluctuations, dissipation, and decoherence of a quantum system of interest. Typically, the bath is modeled as an ensemble of harmonic oscillators, which yields Gaussian statistics of the bath influence on the quantum systems. However, there are also phenomena in which the bath consists of two-state systems, spins, or anharmonic oscillators; theref…

This https://arxiv.org/abs/2205.05941 has been replaced.
link: https://scholar.google.com/scholar?q=a

Decoherence and momentum relaxation in Fermi-polaron Rabi dynamics: a kinetic equation approach
Despite the paradigmatic nature of the Fermi-polaron model, the theoretical description of its nonlinear dynamics poses challenges. Here, we apply a quantum kinetic theory of driven polarons to recent experiments with ultracold atoms, where Rabi oscillations between a Fermi-polaron state and a non-interacting level were reported. The resulting equations separate decoherence from momentum relaxation, with the corresponding rates showing a different dependence on microscopic scattering processes …

This https://arxiv.org/abs/2403.13623 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Fast delivery of heralded atom-photon quantum correlation over 12km fiber through multiplexing enhancement
Distributing quantum entanglement between distant parties is a significant but difficult task in quantum information science, as it can enable numerous applications but suffers from exponential decay in the quantum channel. Quantum repeater is one of the most promising approaches towards this goal. In a quantum repeater protocol, it is essential that the entanglement generation speed within each elementary link is faster than the memory decoherence rate, to enable the scale-up of the quantum re…

This https://arxiv.org/abs/2108.13352 has been replaced.
link: https://scholar.google.com/scholar?q=a

Oxygen Vacancies in Niobium Pentoxide as a Source of Two-Level System Losses in Superconducting Niobium
We identify a major source of quantum decoherence in three-dimensional superconducting radio-frequency (SRF) resonators and two-dimensional transmon qubits composed of oxidized niobium: oxygen vacancies in the niobium pentoxide which drive two-level system (TLS) losses. By probing the effect of sequential \textit{in situ} vacuum baking treatments on the RF performance of bulk Nb SRF resonators and on the oxide structure of a representative Nb sample using time-of-flight secondary ion mass spect…

The impact of noise on the simulation of NMR spectroscopy on NISQ devices
Andisheh Khedri, Pascal Stadler, Kirsten Bark, Matteo Lodi, Rolando Reiner, Nicolas Vogt, Michael Marthaler, Juha Lepp\"akangas
https://arxiv.org/abs/2404.18903

The impact of noise on the simulation of NMR spectroscopy on NISQ devices
We present the simulation of nuclear magnetic resonance (NMR) spectroscopy of small organic molecules with two promising quantum computing platforms, namely IBM's quantum processors based on superconducting qubits and IonQ's Aria trapped ion quantum computer addressed via Amazon Bracket. We analyze the impact of noise on the obtained NMR spectra, and we formulate an effective decoherence rate that quantifies the threshold noise that our proposed algorithm can tolerate. Furthermore we showcase h…

The classical-quantum hybrid canonical dynamics and its difficulties with special and general relativity
Lajos Di\'osi
https://arxiv.org/abs/2404.07723

The classical-quantum hybrid canonical dynamics and its difficulties with special and general relativity
We discuss the Hamiltonian hybrid coupling between a classical and a quantum subsystem. If applicable to classical gravity coupled to quantized matter, this hybrid theory might realize a captivating `postquantum' alternative to full quantum-gravity. We summarize the nonrelativistic hybrid dynamics in improved formalism adequate to Hamiltonian systems. The mandatory decoherence and diffusion terms become divergent in special and general relativistic extensions. It is not yet known if any renorma…

This https://arxiv.org/abs/2311.11461 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Decoherence from Horizons: General Formulation and Rotating Black Holes
Recent work by Danielson, Satishchandran, and Wald (DSW) has shown that black holes -- and, in fact, Killing horizons more generally -- impart a fundamental rate of decoherence on all nearby quantum superpositions. The effect can be understood from measurement and causality: An observer (Bob) in the black hole should be able to disturb outside quantum superpositions by measuring their superposed gravitational fields, but since his actions cannot (by causality) have this effect, the superpositio…

This https://arxiv.org/abs/2404.13883 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Decoherence of a charged Brownian particle in a magnetic field : an analysis of the roles of coupling via position and momentum variables
The study of decoherence plays a key role in our understanding of the transition from the quantum to the classical world. Typically, one considers a system coupled to an external bath which forms a model for an open quantum system. While most of the studies pertain to a position coupling between the system and the environment, some involve a momentum coupling, giving rise to an anomalous diffusive model. Here we have gone beyond existing studies and analysed the quantum Langevin dynamics of a h…

This https://arxiv.org/abs/2402.07969 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Photon-Gravity Coupling in Schwarzschild Spacetime
A canonical formalism for quantum electrodynamics in curved spacetime is developed. This formalism enables a systematic investigation of photons in the Schwarzschild gravitational field, yielding novel results as well as refining previous results that were predicted by heuristic methods. The claim that "the gravitational redshift is a shift in the sharp frequencies of the photons for all frequencies of the spectrum" is proved. It is shown the gravitational superposition decoherence is due to ph…

Decoherence-free algebras in quantum dynamics
Daniele Amato, Paolo Facchi, Arturo Konderak
https://arxiv.org/abs/2403.12926 https://a…

Decoherence-free algebras in quantum dynamics
In this Article we analyze the algebraic properties of the asymptotic dynamics of finite-dimensional open quantum systems in the Heisenberg picture. In particular, a natural product (Choi-Effros product) can be defined in the asymptotic regime. Motivated by this structure, we introduce a new space called the Choi-Effros decoherence-free algebra. Interestingly, this space is both a C* -algebra with respect to the composition product, and a B* -algebra with respect to the Choi-Effros product. Mor…

This https://arxiv.org/abs/2307.00748 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Decoherence Limits the Cost to Simulate an Anharmonic Oscillator
We study how decoherence increases the efficiency with which we can simulate the quantum dynamics of an anharmonic oscillator, governed by the Kerr effect. As decoherence washes out the fine-grained subPlanck structure associated with phase-space quantum interference in the closed quantum system, open quantum dynamics can be more efficiently simulated using a coarse-grained finite-difference numerical integration. We tie this to the way in which decoherence recovers the semiclassical truncated …

This https://arxiv.org/abs/2402.12972 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

The kinematics of multiple Compton scattering of two-photon systems
We present a Stokes-Mueller method to calculate the cross sections associated with multiple Compton scattering of an arbitrary two-photon system. This method is used to calculate the cross section in the scenario in which one of the maximally entangled annihilation photons undergoes intermediate Compton scattering followed by the detection of both photons using a pair of Compton polarimeters. The method accounts for potential quantum-decoherence effects caused by Compton scattering. Despite bei…

Dark versus blocking states in electronic transport: a Lee-Yang zero analysis of full counting statistics
Johann Z\"ollner, Philipp Stegmann, J\"urgen K\"onig, Eric Kleinherbers
https://arxiv.org/abs/2403.09840

Dark versus blocking states in electronic transport: a Lee-Yang zero analysis of full counting statistics
Electronic transport through nanostructures can be suppressed by coherent population trapping, in which quantum coherence leads to a dark state that decouples from the drain electrode. Finite transport, then, relies on decoherence of the dark state. An alternative scenario for reduced transport is weak coupling of a state, referred to as a blocking state, to the drain. This raises the question of whether and how these two scenarios can be distinguished in the transport features. For the example…

This https://arxiv.org/abs/2402.01532 has been replaced.
link: https://scholar.google.com/scholar?q=a

The closed-branch decoder for quantum LDPC codes
Quantum error correction is the building block for constructing fault-tolerant quantum processors that can operate reliably even if its constituting elements are corrupted by decoherence. In this context, real-time decoding is a necessity for implementing arbitrary quantum computations on the logical level. In this work, we present a new decoder for Quantum Low Density Parity Check (QLDPC) codes, named the closed-branch decoder, with a worst-case complexity loosely upper bounded by $\mathcal{O}…

Syncopated Dynamical Decoupling for Suppressing Crosstalk in Quantum Circuits
Bram Evert, Zoe Gonzalez Izquierdo, James Sud, Hong-Ye Hu, Shon Grabbe, Eleanor G. Rieffel, Matthew J. Reagor, Zhihui Wang
https://arxiv.org/abs/2403.07836

Syncopated Dynamical Decoupling for Suppressing Crosstalk in Quantum Circuits
Theoretically understanding and experimentally characterizing and modifying the underlying Hamiltonian of a quantum system is of utmost importance in achieving high-fidelity quantum gates for quantum computing. In this work, we explore the use of dynamical decoupling (DD) in characterizing undesired two-qubit couplings as well as the underlying single-qubit decoherence, and in suppressing them. We develop a syncopated dynamical decoupling technique which protects against decoherence and selecti…

Kinetically constrained models constructed from dissipative quantum dynamics
Somnath Maity, Ryusuke Hamazaki
https://arxiv.org/abs/2403.12548 https://

Kinetically constrained models constructed from dissipative quantum dynamics
We propose a construction of kinetically constrained models using the Markovian quantum dynamics under strong dissipation. Using the Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) formalism, we show that strong dissipation leads to the emergent decoherence-free subspaces, within which constrained quantum many-body unitary dynamics can take place. We argue that the unitary dynamics constructed by the GKSL dynamics is more tightly constrained than that constructed by the strongly interacting Hamilt…

This https://arxiv.org/abs/2402.16824 has been replaced.
link: https://scholar.google.com/scholar?q=a

Quantum correlations in the steady state of light-emitter ensembles from perturbation theory
The coupling of a quantum system to an environment leads generally to decoherence, and it is detrimental to quantum correlations within the system itself. Yet some forms of quantum correlations can be robust to the presence of an environment - or may even be stabilized by it. Predicting (let alone understanding) them remains arduous, given that the steady state of an open quantum system can be very different from an equilibrium thermodynamic state; and its reconstruction requires generically th…

Optimized noise-assisted simulation of the Lindblad equation with time-dependent coefficients on a noisy quantum processor
Jos\'e D. Guimar\~aes, Antonio Ruiz-Molero, James Lim, Mikhail I. Vasilevskiy, Susana F. Huelga, Martin B. Plenio
https://arxiv.org/abs/2402.07617

Optimized noise-assisted simulation of the Lindblad equation with time-dependent coefficients on a noisy quantum processor
Noise in quantum devices is generally considered detrimental to computational accuracy. However, the recent proposal of noise-assisted simulation has demonstrated that noise can be an asset in digital quantum simulations of open systems on Noisy Intermediate-Scale Quantum (NISQ) devices. In this context, we introduce an optimized decoherence rate control scheme that can significantly reduce computational requirements by multiple orders of magnitude, in comparison to the original noise-assisted …

Quantum Walks in Weak Stochastic Gauge Fields
Jan W\'ojcik
https://arxiv.org/abs/2402.09133 https://arxiv.org/pdf/2402.09133

Quantum Walks in Weak Stochastic Gauge Fields
The behaviour of random quantum walks is known to be diffusive. Here we study discrete time quantum walks in weak stochastic gauge fields. In the case of position and spin dependent gauge field, we observe a transition from ballistic to diffusive motion, with the probability distribution becoming Gaussian. However, in contradiction to common belief, weak stochastic electric gauge fields reveal the persistence of Bloch oscillations despite decoherence which we demonstrate on simulations and prov…

This https://arxiv.org/abs/2402.07278 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Dynamically Generated Decoherence-Free Subspaces and Subsystems on Superconducting Qubits
Decoherence-free subspaces and subsystems (DFS) preserve quantum information by encoding it into symmetry-protected states unaffected by decoherence. An inherent DFS of a given experimental system may not exist; however, through the use of dynamical decoupling (DD), one can induce symmetries that support DFSs. Here, we provide the first experimental demonstration of DD-generated DFS logical qubits. Utilizing IBM Quantum superconducting processors, we investigate two and three-qubit DFS codes co…

This https://arxiv.org/abs/2311.04893 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Maximum Entropy Principle as Postulate of Quantum Mechanics
Even a century after the formulation of Quantum Mechanics (QM), the wave function collapse (WFC) remains a contentious aspect of the theory. Environment-induced decoherence has offered a partial resolution by illustrating how unitary evolution in an open quantum system can lead to effective WFC within its components. However, this approach by itself does not lead to a fully self-consistent reformulation of QM. We introduce a modified set of QM postulates, which exclude both WFC and Born's proba…

A Search for Classical Subsystems in Quantum Worlds
Arsalan Adil, Manuel S. Rudolph, Andrew Arrasmith, Zo\"e Holmes, Andreas Albrecht, Andrew Sornborger
https://arxiv.org/abs/2403.10895

A Search for Classical Subsystems in Quantum Worlds
Decoherence and einselection have been effective in explaining several features of an emergent classical world from an underlying quantum theory. However, the theory assumes a particular factorization of the global Hilbert space into constituent system and environment subsystems, as well as specially constructed Hamiltonians. In this work, we take a systematic approach to discover, given a fixed Hamiltonian, (potentially) several factorizations (or tensor product structures) of a global Hilbert…

This https://arxiv.org/abs/2311.11066 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Exotic Symmetry Breaking Properties of Self-Dual Fracton Spin Models
Fracton codes host unconventional topological states of matter and are promising for fault-tolerant quantum computation due to their large coding space and strong resilience against decoherence and noise. In this work, we investigate the ground-state properties and phase transitions of two prototypical self-dual fracton spin models -- the tetrahedral Ising model and the fractal Ising model -- which correspond to error-correction procedures for the representative fracton codes of type-I and type…

This https://arxiv.org/abs/2403.02081 has been replaced.
link: https://scholar.google.com/scholar?q=a

Recovering quantum coherence of a cavity qubit through environment monitoring and active feedback
Decoherence in qubits, caused by their interaction with a noisy environment, poses a significant challenge to developing reliable quantum processors. Monitoring the qubit's environment enables not only to identify decoherence events but also to reverse these errors, thereby restoring the qubit coherence. This approach is particularly beneficial for superconducting cavity qubits, whose unavoidable interaction with auxiliary transmons impacts their coherence. In this work, we uncover the intricat…

Coherent Acoustic Control of Defect Orbital States in the Strong-Driving Limit
B. A. McCullian, V. Sharma, H. Y. Chen, J. C. Crossman, E. J. Mueller, G. D. Fuchs
https://arxiv.org/abs/2403.10989

Coherent Acoustic Control of Defect Orbital States in the Strong-Driving Limit
We use a bulk acoustic wave resonator to demonstrate coherent control of the excited orbital states in a diamond nitrogen-vacancy (NV) center at cryogenic temperature. Coherent quantum control is an essential tool for understanding and mitigating decoherence. Moreover, characterizing and controlling orbital states is a central challenge for quantum networking, where optical coherence is tied to orbital coherence. We study resonant multi-phonon orbital Rabi oscillations in both the frequency and…

This https://arxiv.org/abs/2311.10052 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Entanglement buffering with two quantum memories
Quantum networks crucially rely on the availability of high-quality entangled pairs of qubits, known as entangled links, distributed across distant nodes. Maintaining the quality of these links is a challenging task due to the presence of time-dependent noise, also known as decoherence. Entanglement purification protocols offer a solution by converting multiple low-quality entangled states into a smaller number of higher-quality ones. In this work, we introduce a framework to analyse the perfor…

This https://arxiv.org/abs/2311.04560 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Fast Generation of GHZ-like States Using Collective-Spin XYZ Model
The Greenberger-Horne-Zeilinger (GHZ) state is a key resource for quantum information processing and quantum metrology. The atomic GHZ state can be generated by one-axis twisting (OAT) interaction $H_{\mathrm{OAT}}=χJ_{z}^{2}$ with $χ$ the interaction strength, but it requires a long evolution time $χt=π/2$ and is thus seriously influenced by decoherence and losses. Here we propose a three-body collective-spin XYZ model which creates a GHZ-like state in a very short timescale $χt\sim \ln {…

This https://arxiv.org/abs/2308.14712 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Asymmetric Transmission Through a Classical Analogue of the Aharonov-Bohm Ring
It has been predicted that new physics and technology are enabled for quantum systems that suffer from partial decoherence, in the intermediate range between coherent quantum evolution and incoherent classical physics. We explore the asymmetric transmission through a classical analogue of the Aharonov-Bohm (AB) mesoscopic ring that supports a 3:1 asymmetry in transmission times, augmented with lossy features that act preferentially on the longer-lingering waves. Such a device is realized as a l…

This https://arxiv.org/abs/2402.10897 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Single-photon emitters in WSe$_2$: The critical role of phonons on excitation schemes and indistinguishability
Within optical quantum information processing, single-photon sources based on a two-level system in a semiconductor material allow for on-demand generation of single photons. To initiate the spontaneous emission process, it is necessary to efficiently populate the excited state. However, reconciling the requirement for on-demand excitation with both high efficiency and high photon indistinguishability remains a challenge due to the presence of charge noise and phonon-induced decoherence in the …

This https://arxiv.org/abs/2401.02234 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

One-step implementation of nonadiabatic geometric fSim gate in superconducting circuits
Due to its significant application in reducing algorithm depth, fSim gates have attracted a lot of attention. However, during the implementation of quantum gates, fluctuations in control parameters and decoherence caused by the environment may lead to a decrease in the fidelity of the gate. Implementing the fSim gate that is robust to these factors in one step remains an unresolved issue. In this manuscript, we propose a one-step implementation of the nonadiabatic geometric fSim gate composed o…

This https://arxiv.org/abs/2210.00386 has been replaced.
link: https://scholar.google.com/scholar?q=a

Fourier Transform Noise Spectroscopy
Spectral characterization of noise environments that lead to the decoherence of qubits is critical to developing robust quantum technologies. While dynamical decoupling offers one of the most successful approaches to characterize noise spectra, it necessitates applying large sequences of $π$ pulses that increase the complexity and cost of the method. Here, we introduce a noise spectroscopy method that utilizes only the Fourier transform of free induction decay or spin echo measurements, thus r…