Many-body correlations of electrostatically trapped dipolar excitons
Abstract
We study the photoluminescence (PL) of a two-dimensional liquid of oriented dipolar excitons in In_{x}Ga_{1-x}As coupled double quantum wells confined to a microtrap. Generating excitons outside the trap and transferring them at lattice temperatures down to T = 240 mK into the trap we create cold quasi-equilibrium bosonic ensembles of some 1000 excitons with thermal de Broglie wavelengths exceeding the excitonic separation. With decreasing temperature and increasing density n <= 5*10^10 cm^{-2} we find an increasingly asymmetric PL lineshape with a sharpening blue edge and a broad red tail which we interpret to reflect correlated behavior mediated by dipolar interactions. From the PL intensity I(E) below the PL maximum at E_{0} we extract at T < 5 K a distinct power law I(E) \sim (E_{0}-E)^-|\alpha| with -|\alpha|\sim -0.8 in the range E_{0}-E of 1.5-4 meV, comparable to the dipolar interaction energy.
Keywords
Cite
@article{arxiv.1111.7175,
title = {Many-body correlations of electrostatically trapped dipolar excitons},
author = {G. J. Schinner and J. Repp and E. Schubert and A. K. Rai and D. Reuter and A. D. Wieck and A. O. Govorov and A. W. Holleitner and J. P. Kotthaus},
journal= {arXiv preprint arXiv:1111.7175},
year = {2012}
}