Schomerus, Henning (2011) Universal routes to spontaneous PT-symmetry breaking in non-hermitian quantum systems. Physical review a, 83 (3): 030101. ISSN 1050-2947
Abstract
PT-symmetric systems can have a real spectrum even when their Hamiltonian is non-Hermitian, but develop a complex spectrum when the degree of non-Hermiticity increases. Here we utilize random-matrix theory to show that this spontaneous PT-symmetry breaking can occur via two distinct mechanisms, whose predominance is associated to different universality classes. Present optical experiments fall into the orthogonal class, where symmetry-induced level crossings render the characteristic absorption rate independent of the coupling strength between the symmetry-related parts of the system.