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We propose a method to perform precision measurements of the interaction parameters in systems of N ultra-cold spin 1/2 atoms. The spectroscopy is realized by first creating a coherent spin superposition of the two relevant internal states…

Other Condensed Matter · Physics 2009-11-13 A. M. Rey , L. Jiang , M. D. Lukin

This article studies the decoherence induced on a system of two qubits by local interactions with a spin chain with nontrivial internal dynamics (governed by an XY Hamiltonian). Special attention is payed to the transition between two…

Quantum Physics · Physics 2013-05-29 Cecilia Cormick , Juan Pablo Paz

Mapping the system evolution of a two-state system allows the determination of the effective system Hamiltonian directly. We show how this can be achieved even if the system is decohering appreciably over the observation time. A method to…

We consider a toy model of pointer interacting with a 1/2-spin system, whose $\sigma_{x}$ variable is \emph{measured} by the environment, according to the prescription of decoherence theory. If the environment measuring the variable…

Statistical Mechanics · Physics 2015-06-24 Mauro Bologna , Paolo Grigolini , Marco G. Pala , Luigi Palatella

In this review, we discuss the decoherence and thermalization of a quantum spin system interacting with a spin bath environment, by numerically solving the time-dependent Schr\"{o}dinger equation of the whole system. The effects of the…

Quantum Physics · Physics 2010-05-27 Shengjun Yuan

The prospect of developing magnetic qubits is discussed. The first part of the article makes suggestions on how to achieve the coherent quantum superposition of spin states in small ferromagnetic clusters, weakly uncompensated…

Statistical Mechanics · Physics 2007-05-23 Eugene M. Chudnovsky

By considering an exactly solvable model of a two interacting spin-1/2 qubits described by the Heisenberg anisotropic interaction in the presence of intrinsic decoherence, we study the dynamics of entanglement quantified by the concurrence…

Quantum Physics · Physics 2021-01-29 R. Muthuganesan , V. K. Chandrasekar

The purpose of the present paper is to derive the pointer states of a macro-object using a simple perturbation method. We study the model Hamiltonian involving the weak interaction between the center of mass and its environment. The main…

Quantum Physics · Physics 2016-10-20 Kentaro Urasaki

The use of qubits as sensitive magnetometers has been studied theoretically and recent demonstrated experimentally. In this paper we propose a generalisation of this concept, where a scanning two-state quantum system is used to probe the…

Quantum Physics · Physics 2009-12-10 J. H. Cole , L. C. L. Hollenberg

Environmental decoherence occurs when a quantum system interacts with its surroundings, progressively reducing quantum interference and coherence, complicating the preservation of critical quantum properties over time, especially during…

Quantum Physics · Physics 2025-12-18 Naeem Akhtar , Jia-Xin Peng , Tan Hailin , Xiaosen Yang , Dong Wang

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

We study a class of quantum measurement models. A microscopic object is entangled with a macroscopic pointer such that a distinct pointer position is tied to each eigenvalue of the measured object observable. Those different pointer…

Quantum Physics · Physics 2008-01-29 D. Spehner , F. Haake

We consider a system of two spin-1/2 particles, initially in an entangled Bell state. If one of the particles is interacting with an environment (e.g. a collection of N independent spins), the two-particle system undergoes decoherence.…

Quantum Physics · Physics 2009-12-27 Fedor Levkovich-Maslyuk

We investigate the sensitivity of a recently proposed method for precision measurement [Phys. Rev. Lett. 106, 140502 (2011)], focusing on an implementation based on solid-state spin systems. The scheme amplifies a quantum sensor response to…

Quantum Physics · Physics 2013-02-26 P. Cappellaro , G. Goldstein , J. S. Hodges , L. Jiang , J. R. Maze , A. S. Sørensen , M. D. Lukin

Methods for quantifying environmentally induced decoherence in quantum systems are investigated. We formulate criteria for measuring the degree of decoherence and consider several representative examples, including a spin interacting with…

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

The purpose of the present study is to derive the pointer states of a macroscopic system interacting with its environment, under the general assumptions, i.e., without assuming any form of the interaction Hamiltonian. The lowest order…

Quantum Physics · Physics 2014-04-18 Kentaro Urasaki

We investigate the decoherence properties of a central system composed of two spins 1/2 in contact with a spin bath. The dynamical regime of the bath ranges from a fully integrable integrable limit to complete chaoticity. We show that the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 A. Relano , J. Dukelsky , R. A. Molina

We show that the decoherence, which in the long run destroys quantum features of a system, can be used to reveal the entanglement in a two-qubit system. To this end, we consider a criterion that formally resembles the…

Quantum Physics · Physics 2018-09-07 Jan Krzywda , Piotr Szańkowski , Jan Chwedeńczuk , Łukasz Cywiński

We illustrate through numerical results a number of features of environment-induced decoherence under a broad class of apparatus-environment interactions in quantum measurements wherein the reduced system-apparatus density matrix evolves…

Quantum Physics · Physics 2007-06-13 Avijit Lahiri

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