Transient Loss-Induced Non-Hermitian Degeneracies for Ultrafast Terahertz Metadevices.

ABSTRACT: Non-Hermitian degeneracies, also known as exceptional points (EPs), have attracted considerable attention due to their unique physical properties. In particular, metasurfaces related to EPs can open the way to unprecedented devices with functionalities such as unidirectional transmission and ultra-sensitive sensing. Herein, an active non-Hermitian metasurface with a loss-induced parity-time symmetry phase transition for ultrafast terahertz metadevices is demonstrated. Specifically, the eigenvalues of the non-Hermitian transmission matrix undergo a phase transition under optical excitation and are degenerate at EPs in parameter space, which is accompanied by the collapse of chiral transmission. Ultrafast EP modulation on a picosecond time scale can be realized through variations in the tran

SUBMITTER: He W 

PROVIDER: S-EPMC10754078 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature