Study on high excitation density exciton-polariton Bose Einstein condensation

2014 Fiscal Year Final Research Report

• Project/Area Number: 24740277
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Atomic/Molecular/Quantum electronics
• Research Institution: Yokohama National University (2014); National Institute of Informatics (2012-2013)
• Principal Investigator: HORIKIRI Tomoyuki 横浜国立大学, 工学(系)研究科(研究院), 准教授 (40530275)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 量子光学 / 励起子ポラリトン / ボース・アインシュタイン凝縮 / 半導体マイクロ共振器

Outline of Final Research Achievements

In this study, high density exciton-polariton condensation was investigated. Photoluminescence (PL) by time-resolved spectroscopy in the regime far above condensation threshold (~100 times) was observed. PL showing lower polariton energy at low densities gradually shifted toward higher energy closing to a cavity photon energy as density goes up, and a new higher energy PL peak appeared. The PL dynamics was investigated by theoretical calculations. In addition, we studied the reason of the nonexistence of a lower energy peak which had been expected while there exists a higher energy peak and found that nonequilibrium feature of the exciton-polariton system leads to the observed unbalance in the relative brightness of sidebands. The experimental and theoretical investigations led us to a conclusion that electron-hole binding in the high density regime still seems to exist.

Free Research Field

量子情報