title: Direct measurement of cyclotron coherence times of high-mobility two-dimensional electron gases.
abstract: We have observed long-lived (approximately 30 ps) coherent oscillations of charge carriers due to cyclotron resonance (CR) in high-mobility two-dimensional electrons in GaAs in perpendicular magnetic fields using time-domain terahertz spectroscopy. The observed coherent oscillations were fitted well by sinusoids with exponentially-decaying amplitudes, through which we were able to provide direct and precise measures for the decay times and oscillation frequencies simultaneously. This method thus overcomes the CR saturation effect, which is known to prevent determination of true CR linewidths in high-mobility electron systems using Fourier-transform infrared spectroscopy.
authors.affiliation: Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: D J
authors.initials: DJ
authors.lastname: Hilton
authors.forename: J L
authors.initials: JL
authors.lastname: Reno
authors.forename: D M
authors.initials: DM
authors.lastname: Mittleman
authors.forename: J
authors.initials: J
authors.lastname: Kono