Sommaire:

Non-Hermitian Hamiltonians provide a minimal description of dissipative systems. Non-Hermiticity leads to a wealth of novel phenomena such as the appearance of exceptional points or lines. Importantly, these new features have been harnessed in both quantum and classical experiments, including topological lasers or unidirectional invisibility.
In this talk, I will discuss some of the topological aspects of non-Hermitian systems. Due to generally present non-orthogonality of the orbitals in non-Hermitian Hamiltonians, the stability of topological edge modes to perturbations becomes unclear and requires a reinterpretation of the (Hermitian) bulk-boundary correspondence. In addition, a new set of topological invariants can be defined and directly linked to the non-Hermitian skin effect --- the exponential localization of all single-particle orbitals at one edge. Finally, I will show that shifting from the single-particle picture to the many-body physics in non-Hermitian models is not straightforward, even in the absence of interactions. The interplay between the Pauli exclusion principle and the skin effect leads us to conjecture a novel, fundamentally many-body, bulk-boundary principle.

Pour plus d'informations, merci de contacter Bray C.