Interaction of ultrafast optical pulse with monolayer hexagonal Boron Nitride (h-BN)

Abstract

We theoretically study the interaction of an ultrafast intense circularly polarized optical pulse with monolayer hexagonal Boron Nitride ( h -BN). Such a strong pulse redistributes electrons between the bands and generates a valley-selective conduction band population. The mechanism of producing fundamentally fastest valley polarization in this monolayer has a topological origin. For the moderately large values of pulse duration, both the valley polarization and the residual conduction band population decrease and vanish after a certain value of a pulse duration creating a whole new interference pattern in the reciprocal space. The ultrafast valley polarization in monolayer h -BN may provide a fundamental basis for petahertz-band information processing. • We theoretically study the interaction of an ultrafast circularly polarized optical pulse with h -BN. • The pulse redistributes electrons and generates valley-selective conduction band population. • The fundamentally fastest valley polarization in h -BN monolayer has topological origin. • For the large pulse duration, the valley polarization and conduction band population decrease. • Valley polarization in h -BN may provide a basis for petahertz-band information processing.