Cooling of interacting-exciton gas

Th. Amand, D. Robart, X. Marie +3 more

Леонид Викторович Бутов, C. W. Lai, A. L. Ivanov +2 more

Summary form only given. In the dilute limit excitons behave as weakly interacting Bose particles and are expected to undergo the Bose-Einstein condensation (BEC). Because the exciton mass is very small at experimentally accessible exciton densities the critical temperature for exciton BEC should reach several Kelvins, i.e., about six orders of magnitude higher than the T/sub c/ for atom BEC. To create degenerate Bose-gas of excitons we propose quasi-2D gas of indirect excitons in coupled quantum wells (CQWs) which have two primary advantages for realizing a quantum degenerate exciton gas and, ultimately, the BEC-like phase transition: (i) the long lifetime of indirect excitons and (ii) the short exciton cooling time.

Tokio Ohta

A. P. Kazantsev

S. V. Iordanski, A. Kashuba

We study the kinetics of 2D Bose gas cooling provided Bose particles interact with 3D phonons. At low temperatures, phonon emission is prohibited by energy and momentum conservation. We show that both particle—particle scattering and impurity scattering assist Bose gas cooling. The temporal relaxation of temperature follows the law % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0Jd9sq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaacbaqcKbay-l% qa-Xgagaafaaaa!38AA! $$\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l} $$ above the Berezinski-Kosterlitz-Thouless phase transition point and T∼1/t after a Bose-Einstein 2D quasi-condensate develops.

A. C. H. Cheung, Benjamin D. Simons, P. B. Littlewood