Accession Number:

ADA459983

Title:

Direct Measurement of Population-Induced Broadening of Quantum Well Intersubband Transitions

Descriptive Note:

Journal article

Corporate Author:

CALIFORNIA INST OF TECH PASADENA DEPT OF APPLIED PHYSICS

Report Date:

1997-08-11

Pagination or Media Count:

4.0

Abstract:

In the single band model, also known as the parabolic effective mass model, intersubband transitions in quantum wells QWs are discrete. In practice, electron-electron interaction, QW width nonuniformity, electron interactions with rough interfaces and with impurities and their enhancement by electric fields, and the optical and acoustic phonons contribute to the experimentally observed linewidth of intersubband transition in QWs.1-5 There have been quite a few theoretical reports to explain the experimental observation,1-8 and, there has been controversy over the contribution of population density to the intersubband broadening. Bandara et al.6,7 predicted that the dependence of the exchange interaction on the in-plane momentum k could contribute a substantial fraction of experimentally observed linewidths. Zaluzny,8 on the other hand, claimed that the k dependence is offset by the depolarization and excitonlike manybody effects. In this letter, we report on the experimental study of the dependence of intersubband transition broadening on electron population using a structure consisting of 50 periods of an asymmetric coupled double QWs ACDQWs. External applied bias was used to shift the population between the coupled QWs whose absorption was measured with a monolithically integrated QW infrared photodetector QWIP directly on the ACDQW structure.9,10

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy
  • Quantum Theory and Relativity

Distribution Statement:

APPROVED FOR PUBLIC RELEASE