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The decoherence of a quantum system $S$ coupled to a quantum environment $E$ is considered. For states chosen uniformly at random from the unit hypersphere in the Hilbert space of the closed system $S+E$ we derive a scaling relationship for…

In this study, we propose a spin-star model for spin-(1/2) particles in order to examine the coherence dynamics of a quantum neural network (QNN) unit. Since quantum computing paradigm promises advantages over their classical counterparts,…

Quantum Physics · Physics 2019-05-03 Deniz Türkpençe , Tahir Çetin Akıncı , Serhat Şeker

We study systematically the non-Markovian decoherence dynamics of a dissipative two-level system, i.e., the so-called spin-boson model. It is interesting to find that the decoherence tends to be inhibited with the increase of the coupling…

Quantum Physics · Physics 2013-06-04 Hai-Bin Liu , Jun-Hong An , Chong Chen , Qing-Jun Tong , Hong-Gang Luo , C. H. Oh

For a two-state quantum object interacting with a slow mesoscopic interacting spin bath, we show that a many-body solution of the bath dynamics conditioned on the quantum-object state leads to an efficient control scheme to recover the lost…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Wang Yao , Ren-Bao Liu , L. J. Sham

The central spin model has a wide applicability, it is ideally suited to describe a small quantum system, for instance a quantum bit, in contact to a bath of spins, e.g., nuclear spins, or other small quantum systems in general. According…

Mesoscale and Nanoscale Physics · Physics 2023-03-27 Mohsen Yarmohammadi , Katrin Bolsmann , Yvonne Ribbeheger , Timo Gräßer , Götz S. Uhrig

In this paper a formalism for studying the dynamics of quantum systems coupled to classical spin environments is reviewed. The theory is based on generalized antisymmetric brackets and naturally predicts open-path off-diagonal geometric…

Quantum Physics · Physics 2016-10-21 Alessandro Sergi

We study a simplified Heisenberg spin model in order to clarify the idea of decoherence in closed quantum systems. For this purpose, we define a new concept: the decoherence function \Xi(t), which describes the dynamics of decoherence in…

Quantum Physics · Physics 2007-05-23 Olavi Dannenberg

Decoherence with recurrences appear in the dynamics of the one-body density matrix of an $F = 1$ spinor Bose-Einstein condensate, initially prepared in coherent states, in the presence of an external uniform magnetic field and within the…

Quantum Gases · Physics 2020-12-21 J. C. Sandoval-Santana , R. Zamora-Zamora , R. Paredes , V. Romero-Rochín

We consider the problem of decoherence and relaxation of open bosonic quantum systems from a perspective alternative to the standard master equation or quantum trajectories approaches. Our method is based on the dynamics of expectation…

Quantum Physics · Physics 2009-11-13 D. A. R. Dalvit , G. P. Berman , M. Vishik

We study the application of a new method for simulating nonlinear dynamics of many-body spin systems using quantum measurement and feedback [Mu\~noz-Arias et al., Phys. Rev. Lett. 124, 110503 (2020)] to a broad class of many-body models…

Quantum Physics · Physics 2020-08-19 Manuel H. Muñoz-Arias , Ivan H. Deutsch , Poul S. Jessen , Pablo M. Poggi

We theoretically investigate the dephasing of a central spin-1 model. An interesting mechanism of spin decoherence is found with this model, namely {\em hyperfine mediated spectral diffusion}. This mechanism contains both the features of…

Mesoscale and Nanoscale Physics · Physics 2024-03-18 Rui Li

We present a quantum solution to the electron spin decoherence by a nuclear pair-correlation method for the electron-nuclear spin dynamics under a strong magnetic field and a temperature high for the nuclear spins but low for the electron.…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Wang Yao , Ren-Bao Liu , L. J. Sham

We revisit the problem of decoherence of a qubit centrally coupled to an interacting spin environment, here modeled by a quantum compass chain or an extended XY model in a staggered magnetic field. These two models both support distinct…

Statistical Mechanics · Physics 2017-12-22 R. Jafari , Henrik Johannesson

Spin measurement is studied as a unitary time evolution of the spin coupled to an environment representing the meter and the apparatus. Modelling the environment as a heat bath comprising only a finite number of boson modes and represented…

Quantum Physics · Physics 2022-10-19 Thomas Dittrich , Óscar Rodrí guez , Carlos Viviescas

A model for a quantum register $\cal R$ made of $N$ replicas of a $d$-dimensional quantum system (cell) coupled with the environment, is studied by means of a Born-Markov Master Equation (ME). Dissipation and decoherence are discussed in…

Quantum Physics · Physics 2011-07-19 Paolo Zanardi

We present pulsed electron-nuclear double resonance (ENDOR) experiments which enable us to characterize the coupling between bismuth donor spin qubits in Si and the surrounding spin bath of 29Si impurities which provides the dominant…

Concatenated dynamical decoupling (CDD) pulse sequences hold much promise as a strategy to mitigate decoherence in quantum information processing. It is important to investigate the actual performance of these dynamical decoupling…

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

Dressed spin states, a spin coupling to continuous radiation fields, can fundamentally change how a spin responds to magnetic fluctuations. Using dressed spin states, we were able to protect an electron spin in diamond from decoherence.…

Quantum Physics · Physics 2015-06-22 D. Andrew Golter , Thomas K. Baldwin , Hailin Wang

We study decoherence in a simple quantum mechanical model using two approaches. Firstly, we follow the conventional approach to decoherence where one is interested in solving the reduced density matrix from the perturbative master equation.…

Quantum Physics · Physics 2015-05-20 Jurjen F. Koksma , Tomislav Prokopec , Michael G. Schmidt

We present an analytic approach to treat open quantum systems strongly coupled to multiple environments via noncommuting system operators, a prime example is a qubit concurrently coupled to both decoherring and dissipative baths. Our…

Quantum Physics · Physics 2025-04-23 Jakub Garwoła , Dvira Segal
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