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Related papers: A note on Decoherence and Fractal Hamiltonians

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Quantum mechanics describes the unitary time evolution of closed systems. In practice, every quantum system interacts with the environment leading to an irreversible loss of coherence. The Spin-Boson model (SBM) is central to the…

Chemical Physics · Physics 2020-09-28 Nirmalendu Acharyya , Martin Richter , Benjamin P. Fingerhut

Molecular nanomagnets are quantum spin systems potentially serving as qudits for future quantum technologies thanks to their many accessible low-energy states. At low temperatures, the primary source of error in these systems is pure…

We study decoherence in an interacting qubit system described by infinite range Heisenberg model (IRHM) in a situation where the system is coupled to a bath of local optical phonons. Using perturbation theory in polaron frame of reference,…

Quantum Physics · Physics 2016-01-21 Muzaffar Qadir Lone , Sudhakar Yarlaggada

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 demonstrate in a very general fashion, considerable slowing down of decoherence and relaxation by fast frequency modulation of the system heat bath coupling. The slowing occurs as the decoherence rates are now determined by the spectral…

Quantum Physics · Physics 2021-05-26 G. S. Agarwal

We present the quantum dynamics of a spin coupling to a bath of independent spins via the dissipaton equation of motion (DEOM) approach. The bath, characterized by a continuous spectral density function, is composed of spins that are…

Quantum Physics · Physics 2023-02-02 Wenxiang Ying , Yu Su , Zi-Hao Chen , Yao Wang , Pengfei Huo

A simplified Heisenberg spin model is studied in order to examine the idea of decoherence in closed quantum systems. For this purpose, we present a quantifiable definition to quantum coherence $\Xi$, and discuss in some detail a general…

Quantum Physics · Physics 2008-05-18 Olavi Dannenberg

With the purpose to reveal consistency between multiple quantum (MQ) coherences and entanglement, we investigate numerically the dynamics of these phenomena in one-dimensional linear chains and ring of nuclear spins 1/2 coupled by dipole…

Quantum Physics · Physics 2009-05-26 G. B. Furman , V. M. Meerovich , V. L. Sokolovsky

We study an analytically solvable model for decoherence of a two spin system embedded in a large spin environment. As a measure of entanglement, we evaluate the concurrence for the Bell states (Einstein-Podolsky-Rosen pairs). We find that…

Quantum Physics · Physics 2009-11-11 Zafer Gedik

Decoherence of a localized electron spin in a solid state material (the ``central spin'' problem) at low temperature is believed to be dominated by interactions with nuclear spins in the lattice. This decoherence is partially suppressed…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 W. M. Witzel , S. Das Sarma

We describe our recent results on the resonant perturbation theory of decoherence and relaxation for quantum system with many qubits. The approach represents a rigorous analysis of the phenomenon of decoherence and relaxation for general…

Quantum Physics · Physics 2009-11-17 M. Merkli , G. P. Berman , I. M. Sigal

We consider a finite-dimensional quantum system coupled to a thermal reservoir and subject to a time-periodic, energy conserving forcing. We show that, if a certain dynamical decoupling condition is fulfilled, then the periodic forcing…

Quantum Physics · Physics 2014-02-27 Volker Bach , Walter de Siqueira Pedra , Marco Merkli , Israel Michael Sigal

The central spin decoherence problem has been researched for over 50 years in the context of both nuclear magnetic resonance and electron spin resonance. Until recently, theoretical models have employed phenomenological stochastic…

Mesoscale and Nanoscale Physics · Physics 2012-08-03 Wayne M. Witzel , Malcolm S. Carroll , Lukasz Cywinski , S. Das Sarma

We develop a discrete fermion approach for modelling the strong interaction of an arbitrary system interacting with continuum electronic reservoirs. The approach is based on a pseudo-fermion decomposition of the continuum bath correlation…

We review our recent results on short time approximations, with emphasis on applications for which the system-environment interactions involve a general non-Hermitian system operator and its conjugate. We evaluate the onset of decoherence…

Mesoscale and Nanoscale Physics · Physics 2010-09-22 Vladimir Privman , Denis Tolkunov

We investigate the decoherence process for a quantum register composed of N qubits coupled to an environment. We consider an environment composed of one common phonon bath and several electronic baths. This environment is relevant to the…

Quantum Physics · Physics 2009-11-10 B. Ischi , M. Hilke , M. Dube

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

Real quantum systems couple to their environment and lose their intrinsic quantum nature through the process known as decoherence. Here we present a method for minimizing decoherence by making it energetically unfavorable. We present a…

Quantum Physics · Physics 2009-11-06 D. Bacon , K. R. Brown , K. B. Whaley

The quantum dynamics of a two state system coupled to a bosonic reservoir with sub-Ohmic spectral density is investigated for strong friction. Numerically exact path integral Monte Carlo methods reveal that in contrast to conventional…

Statistical Mechanics · Physics 2015-06-04 Denis Kast , Joachim Ankerhold

Quantum coherence is a key resource underpinning quantum technologies, yet it is highly susceptible to environmental decoherence, especially in thermal settings. While frequency modulation (FM) has shown promise in preserving coherence at…

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