Robust Light State by Quantum Phase Transition in Non-Hermitian Optical Materials

Abstract

Robust light transport is the heart of optical information processing, leading to the search for robust light states by topological engineering of material properties. Here, it is shown that quantum phase transition, rather than topology, can be strategically exploited to design a novel robust light state. We consider an interface between parity-time (PT) symmetric media with different quantum phases and use complex Berry phase to reveal the associated quantum phase transition and topological nature. While the system possesses the same topological order within different quantum phases, phase transition from PT symmetry to PT breaking across the interface in the synthetic non-Hermitian metamaterial system facilitates novel interface states, which are robust against a variety of gain/loss perturbations and topological impurities and disorder. The discovery of the robust light state by quantum phase transition may promise fault-tolerant light transport in optical communications and computing.

Bulk-boundary correspondence in a non-Hermitian system in one dimension with chiral inversion symmetry

“…In parallel, non-Hermitian physics exhibits considerable intriguing features ; the unexpected novel interface states appear between non-Hermitian periodic media with distinct topologies [76][77][78][79][80][81][82][83][84][85][86][87][88][89]. These stimulate the studies of topological phases and edge states in non-Hermitian systems .…”

Topological Hybrid Silicon Microlasers

“…On the other hand, the advent of parity-time-symmetric (and in general non-Hermitian) optical experiments [13][14][15][16][17][18][19][20][21][22][23] has widened the scope by the incorporation of gain and loss, which opens up avenues to explore new phenomena with no electronic analogues. These developments necessitated a reconsideration of the basic notions of topological protection in order to take into account the expanded design parameters space [24][25][26][27][28][29][30][31], and established a connection between topological physics and various separate activities on non-Hermitian photonic systems [32][33][34] .…”

Topological edge modes with PT symmetry in a quasiperiodic structure

“…Parity-time symmetry has been employed to obtain a topological state [35][36][37] or to tailor such states [38,39] within a * nicolas.rivolta@umons.ac.be 1D structure. Here we associate PT symmetry and topology in a 1D quasicrystal device to observe their intriguing combined characteristics.…”