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arXiv · 2305.06406

Fluctuation-dissipation relation in a non-equilibrium quantum fluid

T. R. Kirkpatrick·D. Belitz
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Abstract

There is no simple fluctuation-dissipation theorem (FDT) for nonequilibrium systems. We show that for a fluid in a nonequilibrium steady state (NESS) characterized by a constant temperature gradient there is a generalized FDT that relates commutator correlation functions to the bilinear response of products of observables. This allows for experimental probes of the long-range correlations in such a system, quantum or classical, via response experiments. We also show that the correlations are not tied to thermal fluctuations but are intrinsic to the NESS and reflect a generalized rigidity.

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BibTeXRIS

T. R. Kirkpatrick, D. Belitz. 2023-05-10. Fluctuation-dissipation relation in a non-equilibrium quantum fluid. https://doi.org/10.1103/physrevlett.131.244001

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