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Related papers: Memory effects in a Markov chain dephasing channel

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In this paper, using the notion of nonlinear coherent states, we define a deformed bosonic dephasing channel modelling the impact of a Kerr medium on a quantum state, as it occurs, for instance, in quantum communication based on optical…

Quantum Physics · Physics 2022-11-17 Shahram Dehdashti , Janis Notzel , Peter van Loock

One of the fundamental arguments in quantum information theory is the uncertainty principle. In accordance with this principle, two incompatible observables cannot be measured with high precision at the same time. In this work, we will use…

Quantum Physics · Physics 2024-01-26 Shahram Mehrmanesh , Maryam Hadipour , Soroush Haseli

In the classical RAM, we have the following useful property. If we have an algorithm that uses $M$ memory cells throughout its execution, and in addition is sparse, in the sense that, at any point in time, only $m$ out of $M$ cells will be…

Quantum Physics · Physics 2022-12-22 Harry Buhrman , Bruno Loff , Subhasree Patro , Florian Speelman

Trapped atomic ions enable a precise quantification of the flow of information between internal and external degrees of freedom by employing a non-Markovianity measure [H.-P. Breuer et al., Phys. Rev. Lett. 103, 210401 (2009)]. We reveal…

Quantum Physics · Physics 2018-02-14 Matthias Wittemer , Govinda Clos , Heinz-Peter Breuer , Ulrich Warring , Tobias Schaetz

A phase reference has been a standard requirement in continuous-variable quantum sensing and communication protocols. However, maintaining a phase reference is challenging due to environmental fluctuations, preventing quantum phenomena such…

Quantum Physics · Physics 2021-02-12 Quntao Zhuang

We analyze dephasing in single and double quantum dot systems. The decoherence is introduced by the B\"{u}ttiker model with current conserving fictitious voltage leads connected to the dots. By using the non-equilibrium Green function…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Junren Shi , Zhongshui Ma , X. C. Xie

We study the capacity of a quantum channel where channel acts like controlled phase gate with the control being provided by a one-dimensional quantum spin chain environment. Due to the correlations in the spin chain, we get a quantum…

Quantum Physics · Physics 2017-04-13 Jaideep Mulherkar , V. Sunitha

Non-Markovian processes may arise in physics due to memory effects of environmental degrees of freedom. For quantum non-Markovianity, it is an ongoing debate to clarify whether such memory effects have a verifiable quantum origin, or…

Quantum Physics · Physics 2024-04-18 Charlotte Bäcker , Konstantin Beyer , Walter T. Strunz

We test a general method to detect lower bounds of the quantum channel capacity for two-qubit correlated channels. We consider in particular correlated dephasing, depolarising and amplitude damping channels. We show that the method is…

Quantum Physics · Physics 2016-12-01 Chiara Macchiavello , Massimiliano F. Sacchi

We investigate the dynamical aspects of the quantum switch and find a particular form of quantum memory emerging out of the switch action. We first analyze the loss of information in a general quantum evolution subjected to a quantum switch…

Quantum Physics · Physics 2025-03-26 Vishal Anand , Ananda G. Maity , Subhadip Mitra , Samyadeb Bhattacharya

We consider the coherent stimulated Raman process developing in an optically dense and disordered atomic medium in application to the quantum memory scheme. Our theoretical model predicts that the hyperfine interaction in the excited state…

Quantum Physics · Physics 2010-09-29 A. S. Sheremet , O. S. Mishina , E. Giacobino , D. V. Kupriyanov

This paper investigates the zero-error capacity of channels with memory. Motivated by the nuanced requirements of semantic communication that incorporate memory, we advance the classical enlightened dictator channel by introducing a new…

Information Theory · Computer Science 2024-11-21 Qi Cao , Yulin Shao , Shangwei Ge

We investigate the problem of reversing quantum dynamics, specifically via optimal Petz recovery maps. We focus on typical decoherence channels, such as dephasing, depolarizing and amplitude damping. We illustrate how well a physically…

Quantum Physics · Physics 2022-05-06 Lea Lautenbacher , Fernando de Melo , Nadja K. Bernardes

Quantum technologies rely on the ability to coherently manipulate, process and transfer information, encoded in quantum states, along quantum channels. Decoherence induced by the environment introduces errors, thus setting limits on the…

Quantum Physics · Physics 2013-01-14 Bogna Bylicka , Dariusz Chruściński , Sabrina Maniscalco

In this paper we address the issue of universal or robust communication over quantum channels. Specifically, we consider memoryless communication scenario with channel uncertainty which is an analog of compound channel in classical…

Quantum Physics · Physics 2009-11-13 I. Bjelakovic , H. Boche , J. Noetzel

Generic non-Markovian quantum processes have infinitely long memory, implying an exact description that grows exponentially in complexity with observation time. Here, we present a finite memory ansatz that approximates (or recovers) the…

Quantum Physics · Physics 2021-10-13 Philip Taranto , Felix A. Pollock , Kavan Modi

Arrays of atoms trapped in optical lattices are appealing as storage media for photons, since motional dephasing of the atoms is eliminated. The regular lattice is also associated with band structure in the dispersion experienced by…

Quantum Physics · Physics 2015-05-19 J. Nunn , U. Dorner , P. Michelberger , K. Reim , K. C. Lee , N. K. ~Langford , I. A. Walmsley , D. Jaksch

Advancing quantum technologies necessitates an in-depth exploration of how operations generate quantum resources and respond to noise. Crucial are gates generating quantum coherence and the challenge of mitigating gate dephasing noise.…

Quantum Physics · Physics 2024-03-29 Roberto Salazar , Fereshte Shahbeigi

A simple statistical model for the effects of dephasing on electron transport in one-dimensional quantum systems is introduced, which allows to adjust the degree of phase and momentum randomization independently. Hence, the model is able to…

Mesoscale and Nanoscale Physics · Physics 2012-07-30 Thomas Stegmann , Matías Zilly , Orsolya Ujsághy , Dietrich E. Wolf

We study a hidden Markov process which is the result of a transmission of the binary symmetric Markov source over the memoryless binary symmetric channel. This process has been studied extensively in Information Theory and is often used as…

Dynamical Systems · Mathematics 2015-09-11 Evgeny Verbitskiy