Direct detection of exciton Bose-Einstein Condensation and research on spatio-temporal dynamics

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H06131
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics I
• Research Institution: The University of Tokyo
• Principal Investigator: Morita Yusuke 東京大学, 大学院理学系研究科(理学部), 助教 (60755693)
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: 光物性 / 励起子

Outline of Final Research Achievements

We proceeded research on exciton Bose-Einstein condensation. Inelastic collisions between excitons are obstacle for the realization of exciton BEC. To create a stable condensate, we need to decrease the critical density. For this reason, we have been using a dilution refrigerator. we have developed excitonic Lyman spectroscopy for direct detection. The Lyman spectroscopy is based on detecting 1s-2p induced absorption of mid-infrared light. We have carefully constructed our setup that allows for introducing the mid-infrared probe light into the dilution refrigerator with minimal amount of excess heat. As a result, we have succeeded in conducting the Lyman absorption imaging and luminescence spectroscopy at the 100-mK temperature region.
From absorption imaging, we deduced how density distribution of paraexcitons changes at the high density region. Furthermore, we conducted time-resolved Lyman absorption imaging to know dynamics of paraexcitons clouds.

Free Research Field

光物性物理