Abstract
Electrostatic-doping into an -type Mott insulator has been successfully achieved with use of the heterojunction with an -type band semiconductor Nb-doped . 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 electromodulation 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.
- Received 7 February 2007
DOI:https://doi.org/10.1103/PhysRevB.75.155103
©2007 American Physical Society