Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 14: Symposium Quanten-Hall-Systeme

HL 14.1: Vortrag

Dienstag, 9. März 2004, 10:15–10:45, H15

Radiation induced zero-resistance states in high mobility GaAs/AlGaAs devices — •Ramesh Mani — Harvard University, Gordon McKay Laboratory of Applied Science, 9 Oxford Street, Cambridge, MA 02138 USA — Max-Planck-Institut FkF, Heisenbergstr. 1, 70569 Stuttgart, Germany

We report the experimental detection of novel zero-resistance states [1], which are induced by electromagnetic wave excitation in ultra high mobility GaAs/AlGaAs heterostructure devices including a two-dimensional electron system. Radiation-induced vanishing-resistance states, which do not exhibit concomitant Hall resistance quantization, are demonstrated in the large filling factor, low magnetic field limit, at liquid helium temperatures. It is shown that the observed resistance minima follow the series B = [4/(4j+1)] Bf with j=1,2,., where Bf = 2pfm*/e, m* is an effective mass, e is electron charge, and f is the radiation frequency. The dependence of the effect is reported as a function of experimental parameters such as the electromagnetic wave frequency, incident power, temperature, and the current.