Finite-temperature quantum criticality in a complex-parameter plane
Abstract
A conventional quantum phase transition (QPT) occurs not only at zero temperature, but also exhibits finite-temperature quantum criticality. Motivated by the discovery of the pseudo-Hermiticity of non-Hermitian systems, we explore the finite-temperature quantum criticality in a non-Hermitian PT -symmetric Ising model. We present the complete set of exact eigenstates of the non-Hermitian Hamiltonian, based on which the mixed-state fidelity in the context of biorthogonal bases is calculated. Analytical and numerical results show that the fidelity approach to finite-temperature QPT can be extended to the non-Hermitian Ising model. This paves the way for experimental detection of quantum criticality in a complex-parameter plane.
Cite
@article{arxiv.1506.05553,
title = {Finite-temperature quantum criticality in a complex-parameter plane},
author = {Ci. Li and Zhi. Song},
journal= {arXiv preprint arXiv:1506.05553},
year = {2015}
}
Comments
6 pages, 10 figures