CPT invariant topological phase in non-Hermitian spin-1/2 quantum systems

Non-Hermitian system has recently found its place in laboratories, raising the hope to obtain unconventional and uncharted physical properties. Over the last two to three years, we have made several contributions to time-dependent theory for parity (P), time-reversal (T) invariant non-Hermitian Hamiltonians; delineating its conservation laws, CPT gauge invariance, and new term in the Berry phase. I will talk about a realizable spinful non-Hermitian system exhibiting the non-Abelian Berry phase and supersymmetric edge states.

[1] Non-Abelian Berry Gauge Field and Topological Invariant in Parity-Time Symmetric Non-Hermitian Spin-1/2 Quantum Systems
Ananya Ghatak, Tanmoy Das. arXiv:1907.07333