title: Excited-state fidelity as a signal for the many-body localization transition in a disordered Ising chain.
abstract: In this work, we use exact matrix diagonalization to explore the many-body localization (MBL) transitions in quantum Ising chains with disordered nearest-neighbour couplings, disordered next-nearest-neighbour couplings and disordered external fields. It is demonstrated that the fidelity can be used to characterize the interaction-driven MBL transition in this closed spin system in a manner that is consistent with previous analytical and numerical results. We compute the fidelity for high-energy many-body eigenstates, namely, the excited-state fidelity. It is demonstrated that disordered nearest-neighbour couplings, disordered next-nearest-neighbour couplings and disordered external fields each have different effects on the MBL transition. Furthermore, we investigate the MBL transition of a quantum Ising chain with both disordered nearest-neighbour couplings and disordered next-nearest-neighbour couplings to see how these two types of disordered couplings drive the occurrence of the MBL transition.
authors.affiliation: School of Physics, Northeast Normal University, Changchun, 130024, People's Republic of China. hutt262@nenu.edu.cn.
authors.forename: Taotao
authors.initials: T
authors.lastname: Hu
authors.affiliation: School of Physics, Northeast Normal University, Changchun, 130024, People's Republic of China.
authors.forename: Kang
authors.initials: K
authors.lastname: Xue
authors.affiliation: College of Science, University of Shanghai for Science and Technology, Shanghai, 200093, People's Republic of China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Physics, Northeast Normal University, Changchun, 130024, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Airborne Optical Imaging and Measurement, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033, People's Republic of China.
authors.forename: Hang
authors.initials: H
authors.lastname: Ren