Graphene plasmonic time crystals

The concept of photonic crystals has recently been extended to the time domain and attracted great interest. Unfortunately, realizing photonic time crystals is a challenging task due to the practical difficulty in modulating dielectric constants with large modulation depth. This problem can be resolved by using graphene, the conductivity of which is tunable with significantly large contrast. In this report, graphene plasmonic time crystals, as a new kind of photonic time crystals in atomically thin two‐dimensional material, are proposed and their optical properties are investigated. Their bandstructures are analytically calculated and the propagations of graphene plasmons in temporal crystalline structures are numerically evaluated. Periodically driven by temporally modulating the Fermi energy, graphene plasmons exhibit in‐gap amplification and defects‐immune topological edge states, revealing the nature as plasmonic time crystals. Graphene plasmonic time crystals will be realized soon after this proposal due to the possibility of modulating its conductivity with large contrast by simple electrical gating.This article is protected by copyright. All rights reserved.