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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

We investigate the dynamics of a double quantum dot charge qubit which is coupled to piezoelectric acoustic phonons, appropriate for GaAs heterostructures. At low temperatures, the phonon bath induces a non-Markovian dynamical behavior of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Thorwart , J. Eckel , E. R. Mucciolo

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

We develop an analytical model for describing the dynamics of a donor-based charge quantum bit (qubit). As a result, the quantum decoherence of the qubit is analytically obtained and shown to reveal non-Markovian features: The decoherence…

Quantum Physics · Physics 2015-05-19 F Lastra , S Reyes , S Wallentowitz

A non-equilibrium theory describing the charge qubit dynamics measured by a quantum point contact is developed based on Schwinger-Keldysh's approach. Using the real-time diagram technique, we derive the master equation to all orders in…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Ming-Tsung Lee , Wei-Min Zhang

The dynamics of charge qubit in double quantum dot coupled to phonons is investigated theoretically. The static bias is considered. By means of the perturbation approach based on unitary transformations, the dynamical tunneling current is…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Xiufeng Cao , Hang Zheng

We study the non-Markovian dynamics of a qubit made up of a two-level atom interacting with an electromagnetic field (EMF) initially at finite temperature. Unlike most earlier studies where the bath is assumed to be fixed, we study the…

Quantum Physics · Physics 2009-11-10 S. Shresta , C. Anastopoulos , A. Dragulescu , B. L. Hu

We discuss decoherence due to electromagnetic fluctuations in charge qubits formed by two lateral quantum dots. We use an effective circuit model to evaluate correlations of voltage fluctuations in the qubit setup. These correlations allows…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Diego C. B. Valente , Eduardo R. Mucciolo , F. K. Wilhelm

We evaluate exactly the non-Markovian effect on the decoherence dynamics of a qubit interacting with a dissipative vacuum reservoir and find that the coherence of the qubit can be partially trapped in the steady state when the memory effect…

Quantum Physics · Physics 2015-05-13 Qing-Jun Tong , Jun-Hong An , Hong-Gang Luo , C. H. Oh

The major contribution to decoherence of a double quantum dot or a Josephson junction charge qubit comes from the electrostatic coupling to fluctuating background charges hybridized with the conduction electrons in the reservoir. However,…

Mesoscale and Nanoscale Physics · Physics 2010-09-07 I. V. Yurkevich , J. Baldwin , I. V. Lerner , B. L. Altshuler

We investigate the time-dependent, coherent, and dissipative dynamics of bound particles in single multilevel quantum dots in the presence of sequential tunnelling transport. We focus on the nonequilibrium regime where several channels are…

Mesoscale and Nanoscale Physics · Physics 2010-02-11 Eduardo Vaz , Jordan Kyriakidis

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 dynamics of charge qubit in a double quantum dot coupled to phonons is investigated theoretically in terms of a perturbation treatment based on a unitary transformation. The dynamical tunneling current is obtained explicitly. The result…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Zhuo-Jie Wu , Ka-Di Zhu , Xiao-Zhong Yuan , Yi-Wen Jiang , Hang Zheng

We theoretically investigate the non-equilibrium quantum dynamical theory of a quantum dot system coupled to fermionic reservoirs using the recently developed stochastic fermionic quantum state diffusion (FQSD) equation. The exact or…

Quantum Physics · Physics 2018-12-07 Wufu Shi , Yusui Chen , Lihui Sun , J. Q. You , Ting Yu

The effects of a collection of classical two-level charge fluctuators on the coherence of a dynamically-decoupled qubit are studied. Distinct dynamics are found at different qubit working positions. Exact analytical formulae are derived at…

Mesoscale and Nanoscale Physics · Physics 2015-10-21 Guy Ramon

We microscopically model the decoherence dynamics of entangled coherent states under the influence of vacuum fluctuation. We derive an exact master equation with time-dependent coefficients reflecting the memory effect of the environment,…

Quantum Physics · Physics 2009-06-02 Jun-Hong An , Mang Feng , Wei-Min Zhang

The effects of a nearby two-level charge fluctuator on a double-dot two-spin qubit are studied theoretically. Assuming no direct tunneling between the charge fluctuator and the qubit quantum dots, the Coulomb couplings between the qubit…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Guy Ramon , Xuedong Hu

We investigate the non-Markovian characteristics in continuous measurement of a charge qubit by a quantum point contact. The backflow of information from the reservoir to the system in the non-Markovian domain gives rise to strikingly…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 JunYan Luo , HuJun Jiao , Xiao-Li Lang , BiTao Xiong , Xiao-Ling He

We study the dynamics of a dressed qubit implemented by a spinless fermion hopping between two lattice sites with each site strongly coupled to a bath of phonons. We employ Lang-Firsov transformation to make the problem tractable…

Quantum Physics · Physics 2026-02-10 Saima Bashir , Muzaffar Qadir Lone , Prince A Ganai

Quantum dots are nanometer-scale semiconductor particles that exhibit size-dependent quantum mechanical properties. In this work, we investigate the dynamics of quantum correlations, quantified by the concurrence and the quantum coherence,…

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