Can a photonic thermalization gap arise in disordered non-Hermitian Hamiltonian systems?

¹ School of Electrical, Computer and Energy Engineering, Arizona State University - Tempe, AZ 85287, USA
² Department of Physics, Arizona State University - Tempe, AZ 85287, USA

Received: 7 December 2018
Accepted: 28 January 2019

Abstract

The phenomenon of a chiral-symmetry protected thermalization gap in Hermitian photonic systems is counterintuitive as it implies that the photon coherence can be continuously improved by disorders towards an asymptotic limit. We show that the phenomenon disappears in time-independent, non-Hermitian photonic systems even when the chiral symmetry is well preserved. In fact, the degree of thermalization generally increases with the disorder strength, in agreement with intuition. As non-Hermitian characteristics (e.g., weak gain and loss) can be expected in realistic physical situations, the phenomenon of a thermalization gap may be observed but only in well-controlled experiments with high-quality materials.