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Level Statistics of XXZ Spin Chains with Discrete Symmetries: Analysis through Finite-size Effects

Kazue Kudo·Tetsuo Deguchi
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Abstract

Level statistics is discussed for XXZ spin chains with discrete symmetries for some values of the next-nearest-neighbor (NNN) coupling parameter. We show how the level statistics of the finite-size systems depends on the NNN coupling and the XXZ anisotropy, which should reflect competition among quantum chaos, integrability and finite-size effects. Here discrete symmetries play a central role in our analysis. Evaluating the level-spacing distribution, the spectral rigidity and the number variance, we confirm the correspondence between non-integrability and Wigner behavior in the spectrum. We also show that non-Wigner behavior appears due to mixed symmetries and finite-size effects in some nonintegrable cases.

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Kazue Kudo, Tetsuo Deguchi. 2005-06-03. Level Statistics of XXZ Spin Chains with Discrete Symmetries: Analysis through Finite-size Effects. https://doi.org/10.1143/jpsj.74.1992

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