Fidelity susceptibility for SU(2)-invariant states

Abstract

We study the fidelity susceptibility of two SU(2)-invariant reduced density matrices. Due to the commuting property of these matrices, analytical results for reduced fidelity susceptibility are obtained and can be applied to study quantum phase transitions in SU(2)-invariant systems. As an example, we analyze the quantum criticality of the spin-1 bilinear-biquadratic model via the fidelity approach.