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Main Authors: Attar, Kevin Ben, Bar-Gill, Nir
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2409.12749
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author Attar, Kevin Ben
Bar-Gill, Nir
author_facet Attar, Kevin Ben
Bar-Gill, Nir
contents The study of coherence dynamics in open quantum systems, specifically addressing various physical realizations of quantum systems and environments, is a long-standing and central pillar of quantum science and technology. As such, a large body of work establishes a firm theoretical understanding of these processes. Nevertheless, a fundamental aspect of decoherence dynamics, namely the central limit theorem of qubit dephasing in the central spin model, which leads to a Gaussian approximation, lacks formal proof in realistically relevant scenarios. Here we prove this approximation for a bath depicted by an Ising spin system, in the presence of disorder and several (most relevant) functional forms of qubit-bath coupling. Importantly, we show that in certain cases, namely for short-range (exponentially decaying) coupling, this approximation breaks. These results provide a theoretical framework for studying decoherence dynamics in various systems and lead to insights into dephasing behavior with implications for applications in quantum information, quantum computing, and other quantum technologies.
format Preprint
id arxiv_https___arxiv_org_abs_2409_12749
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Dephasing in the central spin problem with long-range Ising spin-bath coupling
Attar, Kevin Ben
Bar-Gill, Nir
Quantum Physics
The study of coherence dynamics in open quantum systems, specifically addressing various physical realizations of quantum systems and environments, is a long-standing and central pillar of quantum science and technology. As such, a large body of work establishes a firm theoretical understanding of these processes. Nevertheless, a fundamental aspect of decoherence dynamics, namely the central limit theorem of qubit dephasing in the central spin model, which leads to a Gaussian approximation, lacks formal proof in realistically relevant scenarios. Here we prove this approximation for a bath depicted by an Ising spin system, in the presence of disorder and several (most relevant) functional forms of qubit-bath coupling. Importantly, we show that in certain cases, namely for short-range (exponentially decaying) coupling, this approximation breaks. These results provide a theoretical framework for studying decoherence dynamics in various systems and lead to insights into dephasing behavior with implications for applications in quantum information, quantum computing, and other quantum technologies.
title Dephasing in the central spin problem with long-range Ising spin-bath coupling
topic Quantum Physics
url https://arxiv.org/abs/2409.12749