Controlling valley-polarisation in graphene via tailored light pulses

Abstract Analogous to charge and spin, electrons in solids endows an additional degree of freedom: the valley pseudospin. Two-dimensional hexagonal materials such as graphene exhibit two valleys, labelled K ?. These valleys have potential realise logical operations two-dimensional materials. Obtaining desired control over polarisation between is a prerequisite for operations. Recently, it was shown that counter-rotating circularly polarised laser pulses can induce significant valley-polarisation graphene. The main focus present work optimise monolayer by controlling different parameters, wavelength, intensity ratio, frequency ratio sub-cycle phase setup. Moreover, alternate approach, based on single or few-cycle linearly pulse, also explored Our could help experimentalists choose suitable method with optimised parameter space obtain