Sekiguchi Fumiya, Mochizuki Toshimitsu, Kim Changsu, Akiyama Hidefumi, Pfeiffer Loren N, West Ken W, Shimano Ryo
Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan.
Cryogenic Research Center, The University of Tokyo, Tokyo 113-0032, Japan.
Phys Rev Lett. 2017 Feb 10;118(6):067401. doi: 10.1103/PhysRevLett.118.067401. Epub 2017 Feb 8.
We investigate the exciton Mott transition (EMT) by using optical pump-terahertz probe spectroscopy on GaAs, with realizing the condition of Mott's gedanken experiment by the resonant excitation of 1s excitons. We show that an anomalous metallic phase emerges on the verge of the EMT as manifested by a peculiar enhancement of the quasiparticle mass and scattering rate. From the temperature and density dependence, the observed anomaly is shown to originate from the electron-hole (e-h) correlation which becomes prominent at low temperatures, possibly suggesting a precursor of e-h Cooper pairing.
我们通过对砷化镓使用光泵浦-太赫兹探测光谱来研究激子莫特转变（EMT），通过对1s激子的共振激发实现了莫特思想实验的条件。我们表明，在EMT的边缘出现了一个反常金属相，其表现为准粒子质量和散射率的奇特增强。从温度和密度依赖性来看，观察到的反常现象表明源于电子-空穴（e-h）相关性，这种相关性在低温下变得显著，这可能暗示了e-h库珀配对的前兆。
