Phonon induced resistance oscillations (PIRO) caused by THz laser
Abstract
PIRO terms the magneto-resistance (MR) oscillation originating from the resonant interaction of 2D electrons with thermal acoustic phonons, observed only in very high mobility samples (>107 cm2V-1s-1). This manifests itself as a 1/B periodic oscillation of the MR of GaAs/AlGaAs heterostructure, in a temperature range of 4-10 K and high filling factors (magnetic fields below 500 mT). In this work we use THz excitation of the acoustic phonon branch of GaAs by means of a 1.8 THz pulsed quantum cascade laser, so the acoustic phonons are excited by the THz radiation rather than thermally. Electrons resonantly absorb the acoustic phonons accompanied by a 2 kF momentum transfer, causing indirect transitions between Landau levels. The thermally induced PIRO's are not observable in our samples, probably due to the electron mobility being about a factor of two lower than those given in.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MART70313H