Europhys. Lett., 69 (3), pp. 417-423 (2005)
DOI: 10.1209/epl/i2004-10346-7

Ultrafast coherent dynamics of optically inactive excitons in semiconductors

Z. S. Yang, N. H. Kwong, R. Takayama and R. Binder

Optical Sciences Center, University of Arizona - Tucson, AZ 85721, USA

rbinder@u.arizona.edu

received 29 July 2004; accepted in final form 15 November 2004
published online 24 December 2004

Abstract
The center-of-mass momentum distribution of optically created excitons in semiconductors is known to be constrained by the (very small) light momenta at times immediately following the excitation, and it is governed by incoherent scattering processes on longer time scales. The present theoretical analysis suggests that, on intermediate time scales, nonlinear mean-field interactions between excitons lead to a coherent, wave-like evolution in the momentum distribution of optically inactive excitons. Proposals for possible experimental verification of these predictions are discussed.

PACS
71.35.Gg - Exciton-mediated interactions.
78.47.+p - Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter.
78.67.De - Quantum wells.

© EDP Sciences 2005