Resonant Landau Level-Optical Phonon Interaction in Two-Dimensionally Confined Charge Carrier Systems

Abstract

The study of the phenomenon of resonant coupling of Landau level with the longitudinal optical phonon in a bulk semiconductor received considerable impetus with the observation¹ of the anomalous magneto-optical interband absorption behavior of InSb, reported a little over a decade ago. Subsequent studies clarified various aspects of this phenomenon as it affects impurity absorption,² cyclotron resonance³ and combined resonance.⁴ A systematic theoretical study⁵ of the phenomenon in free carrier systems has led to a classification of the relative importance of self-energy and electron-light vertex corrections. In this lecture I shall discuss certain aspects of this phenomenon in the context of the new and novel two-dimensionally confined charge carrier systems that can be made to occur in semiconductor quantum wells,⁶ superlattices^{7, 8} heterojunctions^{9, 10} and the metal-oxide-semiconductor systems.¹¹ The fabrication and study¹² of these systems within the recent past have opened a rather unique opportunity for the exploration of new phenomena arising from the reduced dimensionality, as well as from the special conditions that can be realized in these systems. In addition, new ramifications of established phenomena can be fruitfully employed to gain information regarding fundamental interactions unique to the system.

Research supported by ONR (Contract No.N00014-77-C-0397), by AFSOR (Grant No.AFOSR78-3530) and by the Alfred P. Sloan Founts dation.

Alfred P. Sloan Fellow.