Coherent Control of Ballistic Photocurrents in Multilayer Epitaxial Graphene Using Quantum Interference

Dong Sun (1) , Charles Divin (1) , Julien Rioux (2) , J. E. Sipe (2) , Claire Berger (3) , Walt A. de Heer (4) , Philip N. First (4) , Theodore B. Norris (1)

1 Center for Ultrafast Optical Science
2 Department of Physics [Toronto]
3 NEEL - QuantECA - Circuits électroniques quantiques Alpes
4 School of Physics

We report generation of ballistic electric currents in unbiased epitaxial graphene at 300 K via quantum interference between phase-controlled cross-polarized fundamental and second harmonic 220 fs pulses. The transient currents are detected via the emitted terahertz radiation. Because of graphene's special structure symmetry, the injected current direction can be well controlled by the polarization of the pump beam in epitaxial graphene. This all optical injection of current provides not only a noncontact way of injecting directional current in graphene but also new insight into optical and transport process in epitaxial graphene.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Dong Sun, Charles Divin, Julien Rioux, J. E. Sipe, Claire Berger, et al.. Coherent Control of Ballistic Photocurrents in Multilayer Epitaxial Graphene Using Quantum Interference. Nano Letters, 2010, 10, pp.1293-1296. ⟨10.1021/nl9040737⟩. ⟨hal-01002970⟩