Accession Number : ADA182555

Title :   Thermodynamics of Strain-Confined Paraexcitons in Cu2O.

Descriptive Note : Final rept. 1 Sep 84-28 Feb 87,

Corporate Author : ILLINOIS UNIV AT URBANA LOOMIS LAB OF PHYSICS

Personal Author(s) : Trauernicht,D P ; Wolfe,J P ; Mysyrowicz,A

PDF Url : ADA182555

Report Date : Feb 1987

Pagination or Media Count : 62

Abstract : The thermodynamic behavior of long lived paraexcitons confined to a parabolic potential well is examined. The potential well is produced by a Hertzian contact stress. A wavelength tunable dye laser is used to create excitons directly in the potential well or at any other localized point inside the crystal. Spectral and spatial distributions of the exciton recombination luminescence are measured for CW and pulsed excitation. The possibility of Bose Einstein condensation (BEC) of these long-lived excitons is examined both theoretically and experimentally. We calculate the spectal and spatial distribution of luminescence from a gas of non-interacting particles in a three dimensional harmonic oscillator well. The results are markedly different for direct (no phonon) and indirect (phonon assisted) recombination. The calculated spectra are compared to the data for moderate CW excitation. Taken alone, the no phonon spectra suggest that the excitonic gas is in the quantum regime; however, this conclusion is shown to be inconsistent with the estimated density of the gas.

Descriptors :   *EXCITONS, *COPPER COMPOUNDS, *OXIDES, ESTIMATES, EXCITATION, BEHAVIOR, DENSITY, DYE LASERS, FREQUENCY, GASES, INTERACTIONS, LONG LIFE, LUMINESCENCE, PARABOLAS, PARTICLES, PHONONS, PULSES, QUANTUM THEORY, RECOMBINATION REACTIONS, SPATIAL DISTRIBUTION, SPECTRA, SPECTRAL ENERGY DISTRIBUTION, STRESSES, THERMODYNAMICS, TUNABLE LASERS

Subject Categories : Inorganic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE