2008/03/28 by Xiaoguang Wang, Zhe Sun, Z. D. Wang · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.79.012105
Four pages, two figures
arxiv created 2008/03/28 · arxiv updated 2009/12/01
We introduce the operator fidelity and propose to use its susceptibility for characterizing the sensitivity of quantum systems to perturbations. Two typical models are addressed: one is the transverse Ising model exhibiting a quantum phase transition, and the other is the one dimensional Heisenberg spin chain with next-nearest-neighbor interactions, which has the degeneracy. It is revealed that the operator fidelity susceptibility is a good indicator of quantum criticality regardless of the system degeneracy.