Superradiant Decay of Cyclotron Resonance of Two-Dimensional Electron Gases

Superradiant decay of cyclotron resonance of two-dimensional electron gases.

We report on the observation of collective radiative decay, or superradiance, of cyclotron resonance (CR) in high-mobility two-dimensional electron gases in GaAs quantum wells using time-domain terahertz magnetospectroscopy. The decay rate of coherent CR oscillations increases linearly with the electron density in a wide range, which is a hallmark of superradiant damping. Our fully quantum mech...

Direct measurement of cyclotron coherence times of high-mobility two-dimensional electron gases.

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 direc...

Two-dimensional cyclotron-resonance maser array: Spectral measurements with one and two electron beams

The cyclotron-resonance-maser ~CRM! array is a device in which separate electron beams perform simultaneously a cyclotron interaction with a single Bloch wave in an artificial lattice. The CRM array has the capability of generating high-power microwaves with relatively low-voltage electron beams. The low-voltage operation reduces the system overhead and leads to a relatively compact device. In ...

Tunneling between parallel two-dimensional electron gases.

The tunneling between two parallel two-dimensional electron gases has been investigated as a function of temperature T , carrier density n, and the applied perpendicular magnetic field B. In zero magnetic field the equilibrium resonant lineshape is Lorentzian, reflecting the Lorentzian form of the spectral functions within each layer. From the width of the tunneling resonance the lifetime of th...

InGaAs/GaAsSb based two-dimensional electron gases