Quantum oscillations in an optically-illuminated two-dimensional electron system at the LaAlO3/SrTiO3interface

I Leermakers; K Rubi; M Yang; B Kerdi; M Goiran; W Escoffier; A S Rana; A E M Smink; A Brinkman; H Hilgenkamp; J C Maan; U Zeitler

doi:10.1088/1361-648X/ac211a

Quantum oscillations in an optically-illuminated two-dimensional electron system at the LaAlO₃/SrTiO₃interface

J Phys Condens Matter. 2021 Sep 8;33(46). doi: 10.1088/1361-648X/ac211a.

Authors

I Leermakers¹, K Rubi¹, M Yang², B Kerdi², M Goiran², W Escoffier², A S Rana³, A E M Smink³, A Brinkman³, H Hilgenkamp³, J C Maan¹, U Zeitler¹

Affiliations

¹ High Field Magnet Laboratory (HFML-EMFL) and Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands.
² Laboratoire National des Champs Magnétiques Intenses (LNCMI-EMFL), Université de Toulouse, CNRS, INSA, UPS, 143 Avenue de Rangueil, 31400 Toulouse, France.
³ MESA + Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.

PMID: 34433152
DOI: 10.1088/1361-648X/ac211a

Abstract

We have investigated the illumination effect on the magnetotransport properties of a two-dimensional electron system at the LaAlO₃/SrTiO₃interface. The illumination significantly reduces the zero-field sheet resistance, eliminates the Kondo effect at low-temperature, and switches the negative magnetoresistance into the positive one. A large increase in the density of high-mobility carriers after illumination leads to quantum oscillations in the magnetoresistance originating from the Landau quantization. The carrier density (∼2 × 10¹² cm^-2) and effective mass (∼1.7m_e) estimated from the oscillations suggest that the high-mobility electrons occupy thed_xz/yzsubbands of Ti:t_2gorbital extending deep within the conducting sheet of SrTiO₃. Our results demonstrate that the illumination which induces additional carriers at the interface can pave the way to control the Kondo-like scattering and study the quantum transport in the complex oxide heterostructures.

Keywords: complex oxide interfaces; illumination; magnetoconductance oscillations.

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