Photo-sensitive Transport Properties of the Two-dimensional Electron Gas at LaAlO$_3$/SrTiO$_3$ Interfaces

ORAL

Abstract

Photoresistance has been previously well characterized in highly resistive ($>10^6$ $\Omega/\Box$) LaAlO$_3$/SrTiO$_3$ heterostructures, showing a decrease in resistance on exposure to light. In some cases insulating heterostructures with LaAlO$_3$ layer below the critical thickness have become conducting on exposure to light. Here we report on the effects of light exposure on much lower sheet resistance ($\sim10^4$ $\Omega/\Box$) LaAlO$_3$/SrTiO$_3$ interfaces, which we find to show a non-negligible increase in resistance. This effect is opposite to the behavior of our more resistive samples. We discuss temperature and magnetic field dependence, possible mechanisms for this behavior, and the implications for other transport properties.

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Authors

  • T. Hernandez

    University of Wisconsin-Madison

  • Sangwoo Ryu

    Dept. of Materials Science and Engineering, University of Wisconsin-Madison, Wisconsin 53706, USA, University of Wisconsin-Madison

  • C.W. Bark

    University of Wisconsin-Madison

  • Chang-Beom Eom

    Dept. of Materials Science and Engineering, University of Wisconsin-Madison, Wisconsin 53706, USA, University of Wisconsin-Madison, Department of Materials Sciences and Engineering, University of Wisconsin-Madison

  • Mark Rzchowski

    University of Wisconsin-Madison, University of Wisconsin, Madison