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Published on: August 2, 2019
Finite-temperature fidelity susceptibility for one-dimensional quantum systems
1Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, D-67663 Kaiserslautern, Germany.
Abstract:
We calculate the fidelity susceptibility χf 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 χf(T) analytically for free spinless fermions and numerically for the XXZ chain. Finally, we study χf at the two phase transitions in this model.
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