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Optical probe of electrostatic doping in an n-type Mott insulator

M. Nakamura·A. Sawa·H. Sato·H. Akoh·M. Kawasaki·Y. Tokura
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Abstract

Electrostatic doping into an $n$-type Mott insulator Sm$_{2}$CuO$_{4}$ has been successfully achieved with use of the heterojunction with an $n$-type band semiconductor Nb-doped SrTiO$_{3}$. The junction exhibits rectifying current-voltage characteristics due to the interface band discontinuity and the formation of depleted region. The application of reverse bias electric field on this junction enables the field-effect electron doping (presumably up to 6% per Cu atom) to the Mott insulator. The electro-modulation absorption spectroscopy could clearly show a large modification of the Mott-gap state accompanying the spectral weight transfer to the lower-energy region, reminiscent of formation of a metallic state.

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M. Nakamura, A. Sawa, H. Sato, H. Akoh, M. Kawasaki, Y. Tokura. 2007-02-15. Optical probe of electrostatic doping in an n-type Mott insulator. https://doi.org/10.1103/physrevb.75.155103

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