3,951 research outputs found
Electrical pump-and-probe study of spin singlet-triplet relaxation in a quantum dot
Spin relaxation from a triplet excited state to a singlet ground state in a
semiconductor quantum dot is studied by employing an electrical pump-and-probe
method. Spin relaxation occurs via cotunneling when the tunneling rate is
relatively large, confirmed by a characteristic square dependence of the
relaxation rate on the tunneling rate. When cotunneling is suppressed by
reducing the tunneling rate, the intrinsic spin relaxation is dominated by
spin-orbit interaction. We discuss a selection rule of the spin-orbit
interaction based on the observed double-exponential decay of the triplet
state.Comment: 4 pages, 4 figure
Microwave magnetoplasmon absorption by a 2DEG stripe
Microwave absorption by a high mobility 2DEG has been investigated
experimentally using sensitive Electron Paramagnetic Resonance cavity
technique. It is found that MW absorption spectra are chiefly governed by
confined magnetoplasmon excitations in a 2DEG stripe. Spectra of the 2D
magnetoplasmons are studied as a function of magnetic field, MW frequency and
carrier density. The electron concentration is tuned by illumination and
monitored using optical photoluminescence technique.Comment: to be published in International Journal of Modern Physics
- …