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arXiv · 0808.3514

Logarithmic current fluctuations in non-equilibrium quantum spin chains

Tibor Antal·P. L. Krapivsky·A. Rákos
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Abstract

We study zero-temperature quantum spin chains which are characterized by a non-vanishing current. For the XX model starting from the initial state |... + + + - - - ...> we derive an exact expression for the variance of the total spin current. We show that asymptotically the variance exhibits an anomalously slow logarithmic growth; we also extract the sub-leading constant term. We then argue that the logarithmic growth remains valid for the XXZ model in the critical region.

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Tibor Antal, P. L. Krapivsky, A. Rákos. 2009-01-09. Logarithmic current fluctuations in non-equilibrium quantum spin chains. https://doi.org/10.1103/physreve.78.061115

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