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arXiv · 0907.4545

Pressure Tuning of an Ionic Insulator into a Heavy Electron Metal: An Infrared Study of YbS

M. Matsunami·H. Okamura·A. Ochiai·T. Nanba
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Abstract

Optical conductivity [$σ(ω)$] of YbS has been measured under pressure up to 20 GPa. Below 8 GPa, $σ(ω)$ is low since YbS is an insulator with an energy gap between fully occupied 4$f$ state and unoccupied conduction ($c$) band. Above 8 GPa, however, $σ(ω)$ increases dramatically, developing a Drude component due to heavy carriers and characteristic infrared peaks. It is shown that increasing pressure has caused an energy overlap and hybridization between the $c$ band and 4$f$ state, thus driving the initially ionic and insulating YbS into a correlated metal with heavy carriers.

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M. Matsunami, H. Okamura, A. Ochiai, T. Nanba. 2009-12-16. Pressure Tuning of an Ionic Insulator into a Heavy Electron Metal: An Infrared Study of YbS. https://doi.org/10.1103/physrevlett.103.237202

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