Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging
Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging
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DOI：
10.1126/science.1150124
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发表时间：
2007-12-14
期刊：
影响因子：
56.9
通讯作者：
Basov, D. N.
中科院分区：
文献类型：
--
作者：
Qazilbash, M. M.;Brehm, M.;Basov, D. N.
相关绝缘体中的电子由于它们之间的库仑排斥而不能导电。当通过掺杂或加热在相关绝缘体中诱导绝缘体到金属的转变时，所产生的导电状态可以从根本上不同于传统金属中由自由电子表征的导电状态。我们报告的电子性质的原型相关绝缘体二氧化钒，其中金属态可以通过增加温度诱导。扫描近场红外显微镜使我们能够直接成像纳米级金属水坑出现在绝缘体到金属过渡的开始。结合远场红外光谱，数据揭示了金属熔池中准粒子质量发散的莫特跃迁。所使用的实验方法设置的阶段，在其他非均匀相关电子系统的纳米级上的电荷动力学的调查。
Electrons in correlated insulators are prevented from conducting by Coulomb repulsion between them. When an insulator- to- metal transition is induced in a correlated insulator by doping or heating, the resulting conducting state can be radically different from that characterized by free electrons in conventional metals. We report on the electronic properties of a prototypical correlated insulator vanadium dioxide in which the metallic state can be induced by increasing temperature. Scanning near- field infrared microscopy allows us to directly image nanoscale metallic puddles that appear at the onset of the insulator- to- metal transition. In combination with far- field infrared spectroscopy, the data reveal the Mott transition with divergent quasi- particle mass in the metallic puddles. The experimental approach used sets the stage for investigations of charge dynamics on the nanoscale in other inhomogeneous correlated electron systems.