Fermionic analogue of Hawking radiation in bilayer black phosphorous*

Topological matters upon the periodic driving of laser can lead to nonequilibrium topological states, which is not accessible in equilibrium topological materials. Here we propose that the periodically driven two-dimensional black phosphorous (BP) thin film with a spatial gradient of Floquet-Dirac states can mimic the “gravity” felt by fermionic quasiparticles as that for a Schwarzschild black hole (SBH). Quantum tunneling of electrons from a type-II Dirac cone (inside BH) to a type-I Dirac cone (outside) emits a SBH-like Hawking radiation spectrum. The obtained T_H of a fermionic analog of BH in BP is approximately 3 K, which is several orders of magnitude higher than previous works. Our work sheds some light on increasing the T_H from the perspective of nonequilibrium topological states under periodic driving of laser. The obtained SBH accessible in nonequilibrium BP provides some clues to access the more Fermionic analogues of astronomy phenomena in solids.