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Related papers: A Cutoff Phenomenon for Quantum Markov Chains

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We consider a unified framework of sequential change-point detection and hypothesis testing modeled by means of hidden Markov chains. One observes a sequence of random variables whose distributions are functionals of a hidden Markov chain.…

Optimization and Control · Mathematics 2013-12-13 Savas Dayanik , Kazutoshi Yamazaki

Metastability in open system dynamics describes the phenomena of initial relaxation to longlived metastable states before decaying to the asymptotic stable states. It has been predicted in continuous-time stochastic dynamics of both…

Quantum Physics · Physics 2024-04-10 Yuan-De Jin , Chu-Dan Qiu , Wen-Long Ma

[This is the unpublished supplemental information from 1989 to the paper: J.M. Deutsch, "Quantum statistical mechanics in a closed system." Phys. Rev. A, 43(4), 2046 (1991).] A closed quantum mechanical system does not necessarily give time…

Quantum Physics · Physics 2025-02-25 J. M. Deutsch

It was recently shown by Lubetzky and Peres (2016) and by Sardari (2018) that Ramanujan graphs, i.e., graphs with the optimal spectrum, exhibit cutoff of the simple random walk in an optimal time and have an optimal almost-diameter. We show…

Combinatorics · Mathematics 2022-03-29 Konstantin Golubev , Amitay Kamber

Considerable theoretical and experimental efforts have been devoted to the quench dynamics, in particular, the dynamical quantum phase transition (DQPT) and the steady-state transition. These developments have motivated us to study the…

Quantum Gases · Physics 2020-03-30 Pei Wang , Gao Xianlong

Quantum graphical models (QGMs) extend the classical framework for reasoning about uncertainty by incorporating the quantum mechanical view of probability. Prior work on QGMs has focused on hidden quantum Markov models (HQMMs), which can be…

Machine Learning · Computer Science 2019-03-13 Sandesh Adhikary , Siddarth Srinivasan , Byron Boots

A recent proposal by Hallam et al. suggested using the chaotic properties of the semiclassical equations of motion, obtained by the time dependent variational principle (TDVP), as a characterization of quantum chaos. In this paper, we…

Quantum Physics · Physics 2020-01-20 Yochai Werman

Topological phases, edge states, and flat bands in synthetic quantum systems are a key resource for topological quantum computing and noise-resilient information processing. We introduce a scheme based on step-dependent quantum walks on…

Quantum Physics · Physics 2026-04-07 Dinesh Kumar Panda , Colin Benjamin

Quantum machine learning (QML) shows promise for analyzing quantum data. A notable example is the use of quantum convolutional neural networks (QCNNs), implemented as specific types of quantum circuits, to recognize phases of matter. In…

Quantum Physics · Physics 2025-01-07 Chukwudubem Umeano , Annie E. Paine , Vincent E. Elfving , Oleksandr Kyriienko

We study the existence of densities for distributions of piecewise deterministic Markov processes. We also obtain relationships between invariant densities of the continuous time process and that of the process observed at jump times. In…

Probability · Mathematics 2020-06-03 Piotr Gwiżdż , Marta Tyran-Kamińska

In contrast to the usual quantum systems which have at most a finite number of open spectral gaps if they are periodic in more than one direction, periodic quantum graphs may have gaps arbitrarily high in the spectrum. This property of…

Quantum Physics · Physics 2020-05-26 Pavel Exner , Ondřej Turek

Quantum networks will allow to implement communication tasks beyond the reach of their classical counterparts. A pressing and necessary issue for the design of quantum network protocols is the quantification of the rates at which these…

Quantum Physics · Physics 2020-04-22 Stefan Bäuml , Koji Azuma , Go Kato , David Elkouss

The stochastic--quantum correspondence reinterprets quantum dynamics as arising from an underlying stochastic process on a configuration space. We generalize the correspondence by lifting an arbitrary stochastic kernel $\Gamma$ in finite…

Quantum Physics · Physics 2026-03-27 Jason Doukas

The uncertainty principle limits quantum states such that when one observable takes predictable values there must be some other mutually unbiased observables which take uniformly random values. We show that this restrictive condition plays…

Quantum Physics · Physics 2014-08-12 Oscar C. O. Dahlsten , Andrew J. P. Garner , Vlatko Vedral

Due to the unitary evolution, quantum walks display different dynamical features from that of classical random walks. In contrast to this expectation, in this work, we show that extreme events can arise in unitary dynamics and its…

Quantum Physics · Physics 2025-02-27 Nisarg Vyas , M. S. Santhanam

Unital quantum channels, defined by their property of leaving the maximally mixed state invariant, form an important class of quantum operations. A distinguished subset of these channels can be represented as a probabilistic mixture of…

Quantum Physics · Physics 2026-03-19 Charlotte Bäcker , Konstantin Beyer , Walter T. Strunz

This paper gives a necessary and sufficient condition for a sequence of birth and death chains to converge abruptly to stationarity, that is, to present a cut-off. The condition involves the notions of spectral gap and mixing time. Y. Peres…

Probability · Mathematics 2007-05-23 Persi Diaconis , Laurent Saloff-Coste

This paper proposes groove-like potential structures for the observation of quantum information processing by trapped particles. As an illustration the effect of quantum statistics at a 50-50 beam splitter is investigated. For…

Quantum Physics · Physics 2009-10-31 Erika Andersson , Marcia T. Fontenelle , Stig Stenholm

We review recent progress in attaining a quantitative understanding of the scarring phenomenon, the non-random behavior of quantum wavefunctions near unstable periodic orbits of a classically chaotic system. The wavepacket dynamics…

chao-dyn · Physics 2009-08-14 L. Kaplan

The quantum shutter approach to tunneling time scales (G. Garc\'{\i }a-Calder\'{o}n and A. Rubio, Phys. Rev. A \textbf{55}, 3361 (1997)), which uses a cutoff plane wave as the initial condition, is extended in such a way that a certain type…

Quantum Physics · Physics 2016-08-16 Norifumi Yamada , Gastón García-Calderón , Jorge Villavicencio