Accession Number : ADP007828

Title :   Temporal Oscillations of the Excitonic Absorption in a Magnetic Field,

Corporate Author : WEIZMANN INST OF SCIENCE REHOVOT (ISRAEL)

Personal Author(s) : Bar-Joseph, I. ; Bar-Ad, S.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Optical experiments in semiconductor heterostructures have been widely applied during the last few years to investigate the steady state behavior of 2-D systems in magnetic fields. The dynamics of these systems in the very short time scales received only little interest until very recently, when Stark have looked at the nonlinear dynamics of magneto-excitons in GaAs/AlGaAs multiple quantum wells (MQW). In this paper we report the observation of a transient oscillatory behavior of the magneto-exciton absorption. We show that these oscillations are absorption quantum beats, caused by a coherent superposition between two excited spin polarized excitons. This coherent state persists as long as the excitons exist, for a few 10's of picoseconds! To our knowledge this is the first observation of absorption quantum beats in solids. We show that we can measure by these technique the Lande g factor of the electron and holes in semiconductors.

Descriptors :   *QUANTUM ELECTRONICS, ABSORPTION, DYNAMICS, ELECTRONS, EXCITONS, MAGNETIC FIELDS, MAGNETOS, OBSERVATION, OSCILLATION, SEMICONDUCTORS, SOLIDS, STEADY STATE, TIME, TRANSIENTS, GALLIUM ARSENIDES, ALUMINUM GALLIUM ARSENIDES, ISRAEL.

Subject Categories : Electrooptical and Optoelectronic Devices
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE