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arXiv · 0807.1370

Operator fidelity susceptibility, decoherence and quantum criticality

Xiao-Ming Lu·Zhe Sun·Xiaoguang Wang·Paolo Zanardi
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Abstract

The extension of the notion of quantum fidelity from the state-space level to the operator one can be used to study environment-induced decoherence. state-dependent operator fidelity sucepti- bility (OFS), the leading order term for slightly different operator parameters, is shown to have a nontrivial behavior when the environment is at critical points. Two different contributions to OFS are identified which have distinct physical origins and temporal dependence. Exact results for the finite-temperature decoherence caused by a bath described by the Ising model in transverse field are obtained.

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Xiao-Ming Lu, Zhe Sun, Xiaoguang Wang, Paolo Zanardi. 2008-07-12. Operator fidelity susceptibility, decoherence and quantum criticality. https://doi.org/10.1103/physreva.78.032309

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