Intersubband magnetophonon resonances in quantum cascade structures

摘要

We report on our magnetotransport measurements of GaAs/GaAlAs quantum cascadestructures in a magnetic field of up to 62 T. We observe novel quantumoscillations in tunneling current that are periodic in reciprocal magneticfield. We explain these oscillations as intersubband magnetophonon resonancedue to electron relaxation by emission of either single optical or acousticphonons. Our work also provides a non-optical in situ measurement ofintersubband separations in quantum cascade structures.