Programme

O.7 -- Oral, NCTP-43

Date: Monday, 30 July 2018

Time: 14:40 - 15:00

Anomalous localization at the band center in 1D systems with an imaginary random potential

Ba Phi Nguyen (1,*), Duy Khuong Phung (2), and Kihong Kim (3)

(1) Department of Basic Sciences, Mientrung University of Civil Engineering, 24 Nguyen Du, Tuy Hoa, Vietnam; (2) Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Ba Dinh, Hanoi, Vietnam; (3) Department of Energy Systems Research and Department of Physics, Ajou University, Suwon 16499, Korea (*) Email: nguyenbaphi@muce.edu.vn

We study numerically the localization properties of eigenstates in a one-dimensional disordered lattice characterized by a non-Hermitian disordered Hamiltonian, where both the disorder and the non-Hermiticity are inserted simultaneously into the on-site potential. We calculate the averaged participation number, Shannon entropy, and structural entropy as a function of other parameters. We show that, in the presence of an imaginary random potential, all eigenstates are exponentially localized in the thermodynamic limit and strong anomalous Anderson localization occurs at the band center. In contrast to the usual localization anomalies where a weaker localization is observed, the localization of the eigenstates at the band center is strongly enhanced in the present non-Hermitian model. This phenomenon is associated with the occurrence of a large number of strongly-localized states with pure imaginary energy eigenvalues. Keywords: Anderson localization, non-Hermitian Hamiltonian… Reference: [1]. P. W. Anderson, Phys. Rev. 109, 1492 (1958). [2]. P. G. Silvestrov, Phys. Rev. B 64, 075114 (2001). [3]. A. Basiri, Y. Bromberg, A. Yamilov, H. Cao, and T. Kottos, Phys. Rev. A 90, 043815 (2014).

Presenter: Nguyen Ba Phi