Exceptional point induced lasing dynamics in a non-Hermitian system
Abstract
Non-Hermitian systems exhibit many peculiar dynamic behaviors which never showed up in Hermitian systems. The existence of spectral singularity (SS) for a non-Hermitian scattering center provides a lasing mechanism in the context of quantum mechanics. In this paper we show exactly that a finite system at exceptional point (EP) can also provide an alternative laser solution. We investigate the dynamics of non-Hermitian Su-Schrieffer-Heeger (SSH) model around EP, based on the analysis of parity-time (PT ) and chiral-time (CT ) symmetries of the Hamiltonian. In contrast to the SS lasing mechanism for an infinite system, such an SSH chain acts as an active laser medium at threshold, within which a stationary particle emission can be fired anywhere, rather than a specific location at the non-Hermitian scattering center only. In addition, some relevant peculiar phenomena arising from interference between wave packets are revealed based on the analytical solutions.
Cite
@article{arxiv.1808.07205,
title = {Exceptional point induced lasing dynamics in a non-Hermitian system},
author = {K. L. Zhang and P. Wang and Z. Song},
journal= {arXiv preprint arXiv:1808.07205},
year = {2019}
}
Comments
9 pages, 7 figures