Abstract
Temperature and many-body effects on the intersubband transition in a GaAs/As multiple quantum well are studied using the infrared-absorption technique and the envelope-function-approximation method. In order to explain the measured peak position energy of the intersubband transition and its blueshift observed by decreasing temperature and/or increasing the two-dimensional electron-gas density, a theoretical model is developed which is based on a nonparabolic-anisotropic envelope-function-approximation (NAEFA) method. This model takes into account the many-body corrections, in particular, temperature-dependent electron-electron intrasubband and intersubband exchange and direct Coulomb interaction energies as well as the depolarization and excitonlike shifts within the framework of Zaluzny’s implementation of Ando’s formalism [Phys. Rev. B 43, 4511 (1991)]. Temperature-dependent effective masses, nonparabolicity, conduction-band offsets, the Fermi level, and line-shape broadening are also incorporated in the present NAEFA calculations. Our theory provides a qualitative explanation for the magnitude of the measured temperature blueshift. Additional support for many-body effects is obtained by utilizing the persistent photoeffect measurements.
- Received 27 June 1994
DOI:https://doi.org/10.1103/PhysRevB.50.11618
©1994 American Physical Society