Fidelity susceptibility of the quantum Ising model in the transverse field: The exact solution

TL;DR

This paper provides an exact analytical expression for the fidelity susceptibility of the quantum Ising model in a transverse field, revealing a precise relationship between phases and deriving useful summation formulas.

Contribution

It introduces an exact solution for fidelity susceptibility and establishes a phase correspondence, advancing understanding of quantum phase transitions in the Ising model.

Findings

Exact closed-form expression for fidelity susceptibility

One-to-one correspondence between ferromagnetic and paramagnetic phases

Derived elegant summation formulas

Abstract

We derive an exact closed-form expression for fidelity susceptibility of the quantum Ising model in the transverse field. We also establish an exact one-to-one correspondence between fidelity susceptibility in the ferromagnetic and paramagnetic phases of this model. Elegant summation formulas are obtained as a by-product of these studies.