A helium cryostat with pumping of 3He vapors for optical investigations

被引：2

作者：

Gorbunov, A. V. ^{[1
]}

Demikhov, E. I. ^{[1
,2
,3
]}

Dorozhkin, S. I. ^{[1
]}

Meletov, K. P. ^{[1
,2
]}

Timofeev, V. B. ^{[1
]}

机构：

[1] Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Oblast, Russia

[2] OOO RTI, Chernogolovka 142432, Moscow Oblast, Russia

[3] Russian Acad Sci, PN Lebedev Phys Inst, Moscow 119991, Russia

来源：

INSTRUMENTS AND EXPERIMENTAL TECHNIQUES | 2009年 / 52卷 / 06期

基金：

俄罗斯基础研究基金会;

关键词：

BOSE-EINSTEIN CONDENSATION; EXCITONS;

D O I：

10.1134/S0020441209060256

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The construction of a helium cryostat with pumping of He-3 vapors designed for optical measurements with a high spatial resolution in the temperature range 0.45-4.20 K. The cryostat is equipped with four windows made from fused silica. A studied sample is mounted inside a reservoir filled with liquid He-3 in a holder minimizing the influence of both vibrations and thermal drifts and can stay in the chamber at T = 0.45 K for > 20 h. The cryostat was used to study photoluminescence of GaAs/AlGaAs semiconductor heterostructures. It was revealed that, in a structure with two tunnel-coupled GaAs quantum wells with a width of 120 , the threshold pumping power required for the appearance of a narrow spectral line, which corresponds to the Bose condensate of spatially indirect dipolar excitons, decreases by a factor of 6, as the temperature falls from 1.50 to 0.45 K. In a sample with a single wide (250 ) GaAs quantum well, the distribution patterns of the luminescence of dipolar excitons inside a 5-A mu m circular potential trap were obtained at T = 0.45 K. The spatial resolution of the distributions is no worse than 1.5 A mu m.

引用

页码：888 / 893

页数：6