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

Bogdan Damski

Published 2012-12-07, updated 2013-04-16Version 2

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.