2015/02/28 by Lei Wang, Ye-Hua Liu, Jakub Imriška +2 · 1 citation
Physics and Astronomy · #cond-mat.stat-mech #cond-mat.str-el #physics.comp-ph #quant-ph
paper · pdf · doi:10.1103/physrevx.5.031007
published as Phys. Rev. X 5, 031007 (2015) · new physical insight added in Sec. VI., improved data in Fig. 6
arxiv created 2015/03/10 · arxiv updated 2015/07/16
The fidelity susceptibility is a general purpose probe of phase transitions. With its origin in quantum information and in the differential geometry perspective of quantum states, the fidelity susceptibility can indicate the presence of a phase transition without prior knowledge of the local order parameter, as well as reveal the universal properties of a critical point. The wide applicability of the fidelity susceptibility to quantum many-body systems is, however, hindered by the limited computational tools to evaluate it. We present a generic, efficient, and elegant approach to compute the fidelity susceptibility of correlated fermions, bosons, and quantum spin systems in a broad range of quantum Monte Carlo methods. It can be applied both to the ground-state and non-zero temperature cases. The Monte Carlo estimator has a simple yet universal form, which can be efficiently evaluated in simulations. We demonstrate the power of this approach with applications to the Bose-Hubbard model, the spin-1/2 XXZ model, and use it to examine the hypothetical intermediate spin-liquid phase in the Hubbard model on the honeycomb lattice.