Giant magnetoresistance and luminescence red shift of excitons in GaAs and InGaAs quantum wells in weak magnetic field
Abstract
We have performed a series of experiments with excitons in two similar systems, GaAs/AlGaAs and InGaAs/GaAs coupled quantum wells, subject to electric and magnetic fields parallel to the growth direction. In both cases we observe a red shift of the energy of the indirect exciton luminescence with increasing magnetic field, which saturates at about 0.5 T. Also, the current through the sample decreases and reaches saturation at the same value of magnetic field. We argue that these effects can be explained by the magnetoresistance of the barrier layer between the wells, which increases by a factor of three or more. An increase of the magnetic field will lead to lower mean free path of the carriers, an increase of the effective voltage applied to the quantum wells, and decrease of the current. These effects may be useful for magnetic field sensors.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2002
- Bibcode:
- 2002APS..MART17013D