Optical-field-induced current in dielectrics

1. Optical-field-induced current in dielectrics Upper: Schematic of experiment: Dielectric (silica) is exposed to a few-cycle powerful (~1014W/cm2) control pulse of NIR radiation. A weaker NIR drive pulse drives current between the electrodes Lower : Charged transferred through the dielectric as a function of delay between the two pulses A. Schiffrin, T. Paasch-Colberg, N. Karpowicz, V. Apalkov, D. Gerster, S. Mühlbrandt, M. Korbman, J. Reichert, M. Schultze, S. Holzner, J. V. Barth, R. Kienberger, R. Ernstorfer, V. S. Yakovlev, M. I. Stockman, and F. Krausz, Optical-Field-Induced Current in Dielectrics, Nature doi:10.1038/nature11567 (2012) Scientific Achievement It is predicted theoretically and discovered experimentally that in the presence of a strong (~2V/Å) 4-fs laser pulse, a dielectric (silica) undergoes ultrafast and completely reversible quantum transition to a semi-metallic state where a weaker 4-fs pulse drives electric current ~1 A that follows the field of the drive pulse with less than 1 fs reaction time Significance and Impact It is proven possible to control currents in a hard dielectric (silica) without damaging it by an optical electric field, which reversibly increases conductivity of the solid by a factor of ~1018. This opens up prospects of information processing with petahertz bandwidth Research Details • Microscopic Hamiltonian model predicts ultrafast and reversible (collision free) quantum electron dynamics of the solid with <1 fs bandwidth-limited reaction time