Temporal Parity-Time-Symmetric Metasurfaces

Abstract

In this talk, we present the concept of temporal parity-time-symmetric metasurfaces. In contrast to spatial parity-time symmetric structure, here, the metasurface exhibits gain and loss in the temporal domain, and the gain and loss are virtually created by time-varying lossless reactive components. It is found that the alternation of gain and loss in the temporal domain results in the closing of the momentum bandgap. At the exceptional point where the size of the momentum bandgap becomes zero, the metasurface exhibits an exotic response for pulse illuminations, expressed in the localization and linear growing of the pulse energy.