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Related papers: Analytical model of non-Markovian decoherence in d…

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We investigate the sensing performance of a single-qubit quantum thermometer within a non-Markovian dynamical framework. By employing an exactly numerical hierarchical equations of the motion method, we go beyond traditional paradigms of…

Quantum Physics · Physics 2021-10-18 Ze-Zhou Zhang , Wei Wu

In this article, we report the recent progress on decoherence dynamics of electrons in quantum dot quantum computing systems using the exact master equation we derived recently based on the Feynman-Vernon influence functional approach. The…

Mesoscale and Nanoscale Physics · Physics 2010-05-07 Matisse W. Y. Tu , Ming-Tsung Lee , Wei-Min Zhang

One mechanism of decoherence of anyon qubit due to interaction with edge states is considered. The calculations are made at low temperature in Markovian and "short-time" approximation. Two approximations are compared.

Quantum Physics · Physics 2007-05-23 A. Dementsov

When the nonlinearity of nanomechanical resonator is not negligible, the quantum decoherence of charge qubit is studied analytically. Using nonlinear Jaynes-Cummings model, one explores the possibility of being quantum data bus for…

Quantum Physics · Physics 2015-06-15 C. Cheng , Y. B. Gao

We theoretically study the non-Markovian dynamics of qubit systems coupled to nonequilibrium environments with nonstationary and non-Markovian statistical properties. The reduced density matrix of the single qubit system satisfies a closed…

Quantum Physics · Physics 2020-08-04 Xiangji Cai

The decoherence of a qubit due to a classical non-Gaussian noise with correlation time longer than the decoherence time is discussed for arbitrary working points of the qubit. A method is developed that allows an exact formula for the phase…

Superconductivity · Physics 2009-11-11 J. Bergli , Y. M. Galperin , B. L. Altshuler

In this paper we investigate decoherence times of a double quantum dot (DQD) charge qubit due to it coupling with acoustic phonon baths. We individually consider the acoustic piezoelectric as well as deformation coupling phonon baths in the…

Quantum Physics · Physics 2009-11-11 Xian-Ting Liang

In this lectures, we have described some essential features of loss of coherence by a qubit coupled to the environment. We have first presented well known semiclassical arguments that relate both decoherence and relaxation to the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alex Grishin , Igor V. Yurkevich , Igor V. Lerner

We examine the properties of open quantum systems with respect to their time evolution in different regimes, Markovian and non-Markovian. We analyze their behaviour with respect to their coherent or decoherent time evolution by means of…

Quantum Physics · Physics 2015-04-01 Tarek Khalil , Jean Richert

We develop in the weak coupling approximation a quasi-non-Markovian master equation and study the phenomenon of decoherence during the operation of a controlled-not (CNOT) quantum gate in a quantum computer model formed by a linear chain of…

Quantum Physics · Physics 2012-06-08 Pablo López , Gustavo López

Different approaches in quantifying environmentally-induced decoherence are considered. We identify a measure of decoherence, derived from the density matrix of the system of interest, that quantifies the environmentally induced error,…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Arkady Fedorov , Leonid Fedichkin , Vladimir Privman

In the scale-up of quantum computers, the framework underpinning fault-tolerance generally relies on the strong assumption that environmental noise affecting qubit logic is uncorrelated (Markovian). However, as physical devices progress…

We present a new method for evaluating the response of a moving qubit detector interacting with a scalar field in Minkowski spacetime. We treat the detector as an open quantum system, but we do not invoke the Markov approximation. The…

General Relativity and Quantum Cosmology · Physics 2017-02-01 Dimitris Moustos , Charis Anastopoulos

At first, we generally investigate the short-time decoherence of a qubit nonlinearly coupling with a bath. The measure of the decoherence is chosen as the maximum norm of the deviation density operator. Then we concretely investigate the…

Quantum Physics · Physics 2009-11-10 Xian-Ting Liang , Yong-Jian Xiong

We describe the decoherence process induced on a two-level quantum system in direct interaction with a non-equilibrium environment. The non-equilibrium feature is represented by a non-stationary random function corresponding to the…

Quantum Physics · Physics 2015-06-15 Fernando C. Lombardo , Paula I. Villar

Although quantum coherence is a basic trait of quantum mechanics, the presence of coherences in the quantum description of a certain phenomenon does not rule out the possibility to give an alternative description of the same phenomenon in…

Quantum Physics · Physics 2018-12-07 Andrea Smirne , Dario Egloff , María García Díaz , Martin B. Plenio , Susana F. Huelga

We study decoherence of a quantum dot charge qubit due to coupling to piezoelectric acoustic phonons in the Born-Markov approximation. After including appropriate form factors, we find that phonon decoherence rates are one to two orders of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Serguei Vorojtsov , Eduardo R. Mucciolo , Harold U. Baranger

Distribution functions defined in accord with the quantum theory of measurement are combined with results obtained from the quantum Langevin equation to discuss decoherence in quantum Brownian motion. Closed form expressions for wave packet…

Quantum Physics · Physics 2009-11-10 G. W. Ford , J. T. Lewis , R. F. O'Connell

Models of quantum disentanglement are developed for nanometer-scale molecular charge qubits (MCQs). Two MCQs, $A$ and $B$, are prepared in a Bell state and separated for negligible $A$-$B$ interactions. Interactions between the local…

Quantum Physics · Physics 2020-03-18 Shengyang Zhou , Enrique P. Blair

We develop dynamical non-Markovian description of quantum computing in weak coupling limit, in lowest order approximation. We show that long range memory of quantum reservoir produces strong interrelation between structure of noise and…

Quantum Physics · Physics 2009-11-07 Robert Alicki , Michal Horodecki , Pawel Horodecki , Ryszard Horodecki