Low Temperature Physics: 42, 340 (2016); https://doi.org/10.1063/1.4951700
Fizika Nizkikh Temperatur: Volume 42, Number 5 (May 2016), p. 438-446    ( to contents , go back )

Coherence of Bose–Einstein condensate of dipolar excitons in GaAs/AlGaAs heterostructure

A.V. Gorbunov and V.B. Timofeev

Institute of Solid State Physics RAS, Chernogolovka, Moscow District, 2 Academician Ossipyan str., 142432 Russia
E-mail: gorbunov@issp.ac.ru;
timofeev@issp.ac.ru

pos Анотація:

Received December 15, 2015

Abstract

In the presented paper experiments are discussed related with studies of the coherence of dipolar-exciton Bose condensate in GaAs/AlGaAs heterostructure containing a wide single GaAs quantum well and Shottky gate. Dipolar excitons were photoexcited in the ring trap arising along the perimeter of a window in metal gate under applied electrical voltage. With the help of two-beam interference technique related with interference addition of luminescence-light amplitudes and subsequent analysis of correspondent 1-st order correlators both temporal (longitudinal) and spatial (transversal) coherence of exciton condensate have been explored. The transversal coherence length of exciton condensate has been found to exceed considerably thermal de Broglie wavelength of a dipolar exciton. Coherence of the exciton Bose condensate is confirmed also by experimental studies of the luminescence intensity correlations.

PACS: 71.35.Lk Collective effects (Bose effects, phase space filling, and excitonic phase transitions);
PACS: 73.21.–b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems;
PACS: 78.67.–n Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures.

Key words: spatially-indirect excitons, Bose condensation, coherence.

Published online: March 23, 2016

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