Speaker: Peter Hommelhoff, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany

Abstract: We will discuss strongly driven electrons inside of the semi-metal graphene. We observe coupled intra-band motion and interband transitions when we focus phase-stable two-cycle laser pulses at a graphene ribbon. Based on the waveform-dependence of the induced currents and tight-binding simulations, we can identify the underlying mechanism as Landau-Zener-Stückelberg interferometry, so repeated coherent Landau-Zener transistions leading to the waveform-dependent excitation of a net current. Furthermore we will discuss recent two-color effects in strong-field photoemission at metal needle tips.