Charge dynamics near the electron-correlation induced metal-insulator transition in pyrochlore-type molybdates.
Charge dynamics near the electron-correlation induced metal-insulator transition in pyrochlore-type molybdates.
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DOI：
10.1103/physrevlett.93.266401
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发表时间：
2004-12
影响因子：
8.6
通讯作者：
I. Kézsmárki;N. Hanasaki;D. Hashimoto;S. Iguchi;Y. Taguchi;S. Miyasaka;Y. Tokura
中科院分区：
文献类型：
--
作者：
I. Kézsmárki;N. Hanasaki;D. Hashimoto;S. Iguchi;Y. Taguchi;S. Miyasaka;Y. Tokura
通过测量直流和光电导率，研究了R2Mo2O7 （R=Nd, Sm, Gd, Dy，和Ho）的带宽控制金属绝缘体跃迁（MIT）的系统。验证了电子相关在驱动MIT中的重要作用。随着R离子半径(R)或等效的单电子带宽的改变，T=0 K MIT发生在rc约R （R=Gd）处。T=0 K间隙以δ为比例变量（rc-r）连续消失，而在金属侧，德鲁德重量沿rc方向减小。通过金属态和绝缘态的交叉区域来接近高温非相干态。
The systematics of the bandwidth controlled metal-insulator transition (MIT) are investigated for R2Mo2O7 (R=Nd, Sm, Gd, Dy, and Ho) by measurements of dc and optical conductivity. The substantial role of electron correlation in driving the MIT is verified. With changing the R ionic radius (r) or equivalently the one-electron bandwidth, the T=0 K MIT occurs at rc approximately r(R=Gd). The T=0 K gap continuously vanishes as Delta proportional, variant(rc-r), while at the metallic side the decrease of Drude weight is followed towards rc. A high-temperature incoherent state is approached through crossover regions both from the metallic and the insulating state.