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arXiv · 1006.2522

Finite temperature fidelity susceptibility for one-dimensional quantum systems

J. Sirker
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Abstract

We calculate the fidelity susceptibility chi_f for the Luttinger model and show that there is a universal contribution linear in temperature T (or inverse length 1/L). Furthermore, we develop an algorithm - based on a lattice path integral approach - to calculate the fidelity F(T) in the thermodynamic limit for one-dimensional quantum systems. We check the Luttinger model predictions by calculating chi_f(T) analytically for free spinless fermions and numerically for the XXZ chain. Finally, we study chi_f at the two phase transitions in this model.

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J. Sirker. 2010-10-01. Finite temperature fidelity susceptibility for one-dimensional quantum systems. https://doi.org/10.1103/physrevlett.105.117203

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