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Related papers: Decoherence from spin environments: Loschmidt echo…

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Decoherence is strongly influenced by environmental criticality, with conventional Hermitian critical points typically enhancing the loss of quantum coherence. Here, we show that this paradigm is fundamentally altered in non-Hermitian…

Quantum Physics · Physics 2026-02-17 Mei-Lin Li , Zuo Wang , Liang He

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…

Quantum two-level systems interacting with the surroundings are ubiquitous in nature. The interaction suppresses quantum coherence and forces the system towards a steady state. Such dissipative processes are captured by the paradigmatic…

We consider pure dephasing of Bell states of electron spin qubits interacting with a sparse bath of nuclear spins. Using the newly developed two-qubit generalization of cluster correlation expansion method, we calculate the spin echo decay…

Mesoscale and Nanoscale Physics · Physics 2018-10-09 Damian Kwiatkowski , Łukasz Cywiński

We study the scaling of the decoherence factor of a qubit (spin-1/2) using the central spin model in which the central spin (qubit) is globally coupled to a transverse XY spin chain. The aim here is to study the non-equilibrium generation…

Statistical Mechanics · Physics 2015-06-04 Tanay Nag , Uma Divakaran , Amit Dutta

We investigate decoherence channels that are modelled as a sequence of collisions of a quantum system (e.g., a qubit) with particles (e.g., qubits) of the environment. We show that collisions induce decoherence when a bi-partite interaction…

Quantum Physics · Physics 2009-11-11 Mario Ziman , Vladimir Buzek

We study the decoherence process induced by a spin chain environment on a central spin consisting of R spins and we apply it on the dynamics of quantum correlations (QCs) of three interacting qubits. In order to see the impact of the…

Quantum Physics · Physics 2019-10-31 L. T. Kenfack , M. R. T. Fokou , M. Tchoffo , M. E. Ateuafack , L. C. Fai

A high degree of quantum coherence is a crucial requirement for the implementation of quantum logic devices. Solid state nanodevices seem particularly promising from the point of view of integrability and flexibility in the design. However…

Superconductivity · Physics 2007-05-23 G. Falci , E. Paladino , R. Fazio

Superconducting, flux-based qubits are promising candidates for the construction of a large scale quantum computer. We present an explicit quantum mechanical calculation of the coherent behavior of a flux based quantum bit in a noisy…

Quantum Physics · Physics 2007-05-23 Jonathan L. Habif , Mark F. Bocko

Decoherence and dissipation in quantum systems has been studied extensively in the context of Quantum Brownian Motion. Effective decoherence in coarse grained quantum systems has been a central issue in recent efforts by Zurek and by Hartle…

High Energy Physics - Theory · Physics 2007-05-23 Michael R. Gallis

Assuming a two-qubit system in Werner state which evolves in Heisenberg XY model with Dzyaloshinskii-Moriya (DM) interaction under the effect of different environments. We evaluate and compare quantum entanglement, quantum and classical…

Quantum Physics · Physics 2014-08-21 Mohammad Reza Pourkarimi , Majid Rahnama , Hossein Rooholamini

We study the decoherence properties of a two-level (qubit) system homogeneously coupled to an environmental many-body system at a quantum transition, considering both continuous and first-order quantum transitions. In particular, we…

Statistical Mechanics · Physics 2018-12-04 Ettore Vicari

Decoherence, resulting from unwanted interaction between a qubit and its environment, poses a serious challenge towards the development of quantum technologies. Recently, researchers have started analysing how real-time Hamiltonian learning…

Quantum Physics · Physics 2020-06-24 Eleanor Scerri , Erik M. Gauger , Cristian Bonato

It is commonly stated that decoherence in open quantum systems is due to growing entanglement with an environment. In practice, however, surprisingly often decoherence may equally well be described by random unitary dynamics without…

Quantum Physics · Physics 2009-10-29 Julius Helm , Walter T. Strunz

We study decoherence of one, two, and $n$ non-interacting qubits. Decoherence, measured in terms of purity, is calculated in linear response approximation, making use of the spectator configuration. The environment and its interaction with…

Quantum Physics · Physics 2007-11-30 Carlos Pineda

Quantum computing's potential for exponential speedup is fundamentally limited by decoherence, a phenomenon arising from environmental interactions. Non-Hermitian quantum mechanics, particularly $PT$-symmetric systems, offers a novel…

Quantum Physics · Physics 2025-11-25 Duttatreya , Ipsika Mohanty , Sanjib Dey

We explore a strategy for protecting the evolution of a qubit against the effects of environmental noise based on the application of controlled time-dependent perturbations. In the case of a purely decohering coupling, an explicit sequence…

Quantum Physics · Physics 2007-05-23 Lorenza Viola , Seth Lloyd

The spurious interaction of quantum systems with their environment known as decoherence leads, as a function of time, to a decay of coherence of superposition states. Since the interactions between system and environment are local, they can…

Quantum Physics · Physics 2015-03-19 Gonzalo A. Alvarez , Dieter Suter

We study decoherence induced on a two-level system coupled to a one-dimensional quantum spin chain. We consider the cases where the dynamics of the chain is determined by the Ising, XY, or Heisenberg exchange Hamiltonian. This model of…

A persistent current qubit has two quantum states with opposite currents flowing in a superconducting loop. Their magnetic field couple to nuclear spins. The qubit state is not only perturbed by the spins but it also gets entangled with the…

Condensed Matter · Physics 2007-05-23 Jacek Dziarmaga