Direct observation of excitonic polaron in InAs/GaAs quantum dots
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS Hefei, 230026, PRC
2 State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, CAS P.O. Box 912, Beijing 100083, PRC
Accepted: 3 May 2010
We report a direct observation of excitonic polaron in InAs/GaAs quantum dots using the photoluminescence (PL) spectroscopy. We observe that a new peak s' emerges below the s-shell which has anomalous temperature dependence emission energy. The peak s' anticrosses with s at a certain temperature, with a large anticrossing gap up to 31 meV. The behavior of the new peak, which cannot be interpreted using Huang-Rhys model, provides a direct evidence for strong coupling between exciton and LO phonons, and the formation of the excitonic polaron. The strong coupling between exciton and phonons opens a way to coherently control the polaron states.
PACS: 71.38.-k – Polarons and electron-phonon interactions / 71.35.-y – Excitons and related phenomena / 78.67.Hc – Quantum dots
© EPLA, 2010