Non-Hermitian Many-Body Localization in Coupled Hatano-Nelson Interacting Chains
Kuldeep Suthar1*, Yi-Cheng Wang1,2, Yi-Ping Huang3, Jhih-Shih You4, Hsiang-Hua Jen1
1Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
2Department of Physics, National Taiwan University, Taipei, Taiwan
3Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
4Department of Physics, National Taiwan Normal University, Taipei, Taiwan
* Presenter:Kuldeep Suthar,
The physics of non-Hermitian systems has attracted significant interests in recent years. The phenomena of
non-Hermiticity originate from an exchange of energy or particles with environment and leads to several rich
properties such as parity-time symmetry breaking, exceptional points unique to non-Hermitian topology etc.
Recently, it has been shown that a non-Hermitian system with random disorder or quasi-periodic potential
possessing time-reversal symmetry exhibit complex-real transition. In this work, we study the many-body
localization in coupled Hatano-Nelson interacting chains. In contrast to the previous studies of the spinless
fermionic system, the two-chain system shows a complex-real transition which does not coincide to the
localization transition. Moreover, the critical coupling strength of the transition decreases as the ratio of
respective non-reciprocal hopping varied. We further investigate the two-chain model with gain-loss terms,
and study the localization and eigen-spectrum properties of the system. Our study opens up a direction
towards an exploration of the critical effects of disordered non-Hermitian many-body systems in cold-atom

Keywords: Many-body localization, Non-Hermitian Systems, Disordered Systems, Optical lattices, Ultracold atoms