Electronic Structures and Carrier Correlation in Single Pair of Coupled Quantum Dots

• Published in: Japanese Journal of Applied Physics Vol. 44; no. 4S; p. 2647
• Main Authors: Yamauchi, Shohgo, Komori, Kazuhiro, Morohashi, Isao, Goshima, Keishiro, Sugaya, Takeyoshi
• Format: Journal Article
• Language: English
• Published: 01.04.2005
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.44.2647

The electronic structures and carrier correlation in a single pair of InAs/GaAs coupled quantum dots (QDs) are investigated by performing photoluminescence (PL), one-color photoluminescence excitation (PLE) and two-color PLE measurements. Luminescence from the bonding (X + ) and anti-bonding (X - ) states due to the wave function coupling was observed in the micro-PL (µ-PL) spectra of the coupled QDs. One-color PLE spectra reveal the electronic structures of the coupled QD system in which there is the coexistence of both common excited level series between the X + and X - states and individual excited level series for each state. In two-color PLE measurement, the suppression of PLE peak intensity at the energy separation of the longitudinal optical (LO) phonon suggests a carrier correlation through the screening effect of the carrier–LO-phonon interaction in the coupled QD system. Additionally, we demonstrate the control of the energy state in the coupled QDs using two-color excitations.