Direct Measurement of Population-Induced Broadening of Quantum Well Intersubband Transitions
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
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 11, 1997
- Accession Number
- ADA459983
Entities
People
- Ali Shakouri
- Amnon Yariv
- Gilad Almogy
- John O'brien
- Randal A. Salvatore
- Weihua Xu
- Yuanjian Xu
Organizations
- California Institute of Technology