Long-range electronic reconstruction to a dxz,yz-dominated Fermi surface below the LaAlO3/SrTiO3 interface

Authors

Alexander Paul Petrović, Nanyang Technological University, SingaporeFollow
A. Pare, Nanyang Technological University, Singapore
Tula R. Paudel, University of Nebraska-LincolnFollow
K. Lee, Nanyang Technological University, Singapore
S. Holmes, Toshiba Research Europe Ltd., Cambridge Research Laboratory, Cambridge, United Kingdom
Crispin H.W. Barnes, University of CambridgeFollow
A. David, Nanyang Technological University, Singapore
T. Wu, Nanyang Technological University, Singapore
Evgeny Y. Tsymbal, University of Nebraska-LincolnFollow
C. Panagopoulos, Nanyang Technological University, Singapore

Date of this Version

6-18-2014

Citation

SCIENTIFIC REPORTS 4, 5338 (2014). DOI: 10.1038/srep05338

Comments

Copyright 2014 NATURE PUBLISHING GROUP. Used by permission.

Abstract

Low dimensionality, broken symmetry and easily-modulated carrier concentrations provoke novel electronic phase emergence at oxide interfaces. However, the spatial extent of such reconstructions - i.e. the interfacial ‘‘depth’’ - remains unclear. Examining LaAlO₃/SrTiO₃ heterostructures at previously unexplored carrier densities n_2D 14 cm^-2 , we observe a Shubnikov-de Haas effect for small in-plane fields, characteristic of an anisotropic 3D Fermi surface with preferential d_xz,yz orbital occupancy extending over at least 100 nm perpendicular to the interface. Quantum oscillations from the 3D Fermi surface of bulk doped SrTiO₃ emerge simultaneously at higher n_2D. We distinguish three areas in doped perovskite heterostructures: narrow (nm) 2D interfaces housing superconductivity and/or other emergent phases, electronically isotropic regions far (>120 nm) from the interface and new intermediate zones where interfacial proximity renormalises the electronic structure relative to the bulk.