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arXiv · 1807.01674

Ground-state fidelity at first-order quantum transitions

Davide Rossini·Ettore Vicari
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Abstract

We analyze the scaling behavior of the fidelity, and the corresponding susceptibility, emerging in finite-size many-body systems whenever a given control parameter $λ$ is varied across a quantum phase transition. For this purpose we consider a finite-size scaling (FSS) framework. Our working hypothesis is based on a scaling assumption of the fidelity in terms of the FSS variables associated to $λ$ and to its variation $δλ$. This framework entails the FSS predictions for continuous transitions, and meanwhile enables to extend them to first-order transitions, where the FSS becomes qualitatively different. The latter is supported by analytical and numerical analyses of the quantum Ising chain along its first-order quantum transition line, driven by an external longitudinal field.

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Davide Rossini, Ettore Vicari. 2018-11-30. Ground-state fidelity at first-order quantum transitions. https://doi.org/10.1103/physreve.98.062137

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