Doping-dependent band structure of LaAlO3/SrTiO3 interfaces by soft x-ray polarization-controlled resonant angle-resolved photoemission

Cancellieri C;Reinle Schmitt M. L;Kobayashi M;Strocov V. N;Willmott P. R;Fontaine D;Ghosez P;FILIPPETTI, ALESSIO;Delugas P;FIORENTINI, VINCENZO

2014-01-01

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Abstract

olarization-controlled synchrotron radiation was used to map the electronic structure of buried conducting interfaces of LaAlO3/SrTiO3 in a resonant angle-resolved photoemission experiment. A strong polarization dependence of the Fermi surface and band dispersions is demonstrated, highlighting different Ti 3d orbitals involved in two-dimensional (2D) conduction. Measurements on samples with different doping levels reveal dif- ferent band occupancies and Fermi-surface areas. The photoemission results are directly compared with advanced first-principles calculations, carried out for different 3d-band filling levels connected with the 2D mobile carrier concentrations obtained from transport measurements, with indication of charge localization at the interface.