Graphene under a few-cycle circularly polarized optical field: ultrafast interferometry and Berry phase manifestation

We propose an attosecond strong optical field interferometry in graphene which reveals the chirality of graphene without employing a magnetic field. A circularly polarized optical pulse with strong amplitude and femtosecond time scale causes the electron to circle in the reciprocal space through which it accumulates the dynamic phase along the closed trajectory as well as the nontrivial geometric phase known as Berry's phase. The resulting interference fringes carry rich information about the electronic spectra and interband dynamics in graphene near the Dirac points. Our findings hold promise for the attosecond control and measurement of electron dynamics in condensed matters as well as understanding the topological nature of the two-dimensional Dirac materials.