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To control and utilize quantum features in small scale for practical applications such as quantum transport, it is crucial to gain deep understanding of quantum characteristics of states such as coherence. Here by introducing a technique…

Quantum Physics · Physics 2018-01-03 Laleh Memarzadeh , Azam Mani

We study a general quantum system interacting with environment modeled by the bosonic heat bath of Caldeira and Leggett type. General interaction Hamiltonians are considered that commute with the system's Hamiltonian so that there is no…

Quantum Physics · Physics 2014-11-18 D. Mozyrsky , V. Privman

In the framework of the Lindblad theory for open quantum systems, we determine the degree of quantum decoherence of a harmonic oscillator interacting with a thermal bath. It is found that the system manifests a quantum decoherence which is…

Quantum Physics · Physics 2009-11-13 A. Isar

We analyze the evolution of a quantum Brownian particle starting from an initial state that contains correlations between this system and its environment. Using a path integral approach, we obtain a master equation for the reduced density…

Quantum Physics · Physics 2009-10-30 Luciana Dávila Romero , Juan Pablo Paz

The dynamics of a spin-1/2 particle coupled to a nuclear spin bath through an isotropic Heisenberg interaction is studied, as a model for the spin decoherence in quantum dots. The time-dependent polarization of the central spin is…

Quantum Physics · Physics 2007-06-28 D. D. Bhaktavatsala Rao , V. Ravishankar , V. Subrahmanyam

We study the temporal evolution of entanglement pertaining to two qubits interacting with a thermal bath. In particular we consider the simplest nontrivial spin bath models where symmetry breaking occurs and treat them by mean field…

Quantum Physics · Physics 2009-11-10 Marco Lucamarini , Simone Paganelli , Stefano Mancini

We consider a particle coupled to a dissipative environment and derive a perturbative formula for the dephasing rate based on the purity of the reduced probability matrix. We apply this formula to the problem of a particle on a ring, that…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Doron Cohen , Baruch Horovitz

The well-known increase of the decoherence rate with the temperature, for a quantum system coupled to a linear thermal bath, holds no longer for a different bath dynamics. This is shown by means of a simple classical non-linear bath, as…

Quantum Physics · Physics 2011-03-23 A. Montina , F. T. Arecchi

The conventional conception of decoherence relies on the interaction with an external set of degrees of freedom - the 'bath' - to which the system loses quantum information. But the role of the bath can be played too by any internal degrees…

Quantum Gases · Physics 2019-09-20 L. Rico-Pérez

We investigate in detail, using both analytical and numerical tools, the decoherence of electron spins in quantum dots (QDs) coupled to a bath of nuclear spins in magnetic fields or with various initial bath polarizations, focusing on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Wenxian Zhang , V. V. Dobrovitski , K. A. Al-Hassanieh , E. Dagotto , B. N. Harmon

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…

Quantum Physics · Physics 2024-04-24 Suraka Bhattacharjee , Koushik Mandal , Supurna Sinha

We have studied the quantum dissipative problem of a Gaussian wave packet under the influence of a harmonic potential. A phenomenological approach to dissipation is adopted in the light of the well-known model in which the environment is…

Quantum Physics · Physics 2014-11-11 A. Cidrim , F. E. A. dos Santos , A. O. Caldeira

A free particle coupled to a heat bath can exhibit a number of thermodynamic anomalies like a negative specific heat or reentrant classicality. These low-temperature phenomena are expected to be modified at very low temperatures where…

Statistical Mechanics · Physics 2014-04-11 Robert Adamietz , Gert-Ludwig Ingold , Ulrich Weiss

We study a model of dephasing (decoherence) in a two-state quantum system (qubit) coupled to a bath of harmonic oscillators. An exact analytic solution for the reduced dynamics of a two-state system in this model has been obtained…

Quantum Physics · Physics 2015-05-28 V. G. Morozov , S. Mathey , G. Röpke

We show a completely analytical approach to the decoherence induced by a zero temperature environment on a Brownian test particle. We consider an Omhic environment bilinearly coupled to an oscillator and compute the master equation. From…

Quantum Physics · Physics 2016-09-08 Fernando C. Lombardo , Paula I. Villar

A relationship between the time scales of quantum coherence loss and short-time solvent response for a solute/bath system is derived for a Gaussian wave packet approximation for the bath. Decoherence and solvent response times are shown to…

Quantum Physics · Physics 2009-10-31 Oleg V. Prezhdo , Peter J. Rossky

We analyze collisional decoherence of atoms or molecules prepared in a coherent superposition of nondegenerate internal states at ultralow temperatures and placed in an ultracold buffer gas. Our analysis is applicable for an arbitrary bath…

Quantum Physics · Physics 2015-05-14 C. J. Hemming , R. V. Krems

We study the decoherence of two coupled spins that interact with a spin-bath environment. It is shown that the connectivity and the coupling strength between the spins in the environment are of crucial importance for the decoherence of the…

Quantum Physics · Physics 2008-10-22 Shengjun Yuan , Mikhail I. Katsnelson , Hans De Raedt

A general method for obtaining the decoherence time in self-induced decoherence is presented. In particular, it is shown that such a time can be computed from the poles of the resolvent or of the initial conditions in the complex extension…

Quantum Physics · Physics 2009-11-11 Mario Castagnino , Olimpia Lombardi

The dynamics of a qubit in two different environments are investigated theoretically. The first environment is a two level system coupled to a bosonic bath. And the second one is a damped harmonic oscillator. Based on a unitary…

Quantum Physics · Physics 2013-11-05 Peihao Huang , Hang Zheng