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arXiv · 0708.0468

Direct observation of excitonic polaron in InAs/GaAs quantum dots

Ming Gong·Chuan-Feng Li·Geng Chen·Lixin He·F. W. Sun·Guang-Can Guo·Zhi-Chuan Niu·She-Song Huang·Yong-Hua Xiong·Hai-Qiao Ni
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Abstract

Excitonic polaron is directly demonstrated for the first time in InAs/GaAs quantum dots with photoluminescence method. A new peak ($s'$) below the ground state of exciton ($s$) comes out as the temperature varies from 4.2 K to 285 K, and a huge anticrossing energy of 31 meV between $s'$ and $s$ is observed at 225 K, which can only be explained by the formation of excitonic polaron. The results also provide a strong evidence for the invalidity of Huang-Rhys formulism in dealing with carrier-longitudinal optical phonon interaction in quantum dot. Instead, we propose a simple two-band model, and it fits the experimental data quite well. The reason for the finding of the anticrossing is also discussed.

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Ming Gong, Chuan-Feng Li, Geng Chen, Lixin He, F. W. Sun, Guang-Can Guo, Zhi-Chuan Niu, She-Song Huang, Yong-Hua Xiong, Hai-Qiao Ni. 2007-08-15. Direct observation of excitonic polaron in InAs/GaAs quantum dots. https://arxiv.org/abs/0708.0468

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