Domain-induced conductivity anisotropy in LaAlO3/SrTiO3 interface

Xi Wang ^1,2 Eylon Perskey ^1,2 Thierry C. van Thiel ³ Edouard Lesne ^3,4 Alexander Lau ⁵ Mario Cuoco ^6,7 Marc Gabay ⁸ Carmine Ortix ^7,9 Andrea D. Caviglia ^3,10 Beena Kalisky ^1,2

¹Department of Physics, Bar-Ilan University, Ramat-Gan, Israel
²Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel
³Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628CJ Delft, Netherlands
⁴Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
⁵International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
⁶CNR-SPIN, Consiglio Nazionale delle Ricerche, Roma, Italy
⁷Dipartimento di Fisica "E. R. Caianiello", Universita di SalernoItaly, IT-84084 Fisciano, Italy
⁸Laboratoire de Physique des Solides, Universite Paris-Saclay, CNRS UMR 8502, Orsay, France
⁹Center for Extreme Matter and Emergent Phenomena, Institute for Theoretical Physics, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands
¹⁰Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland

Conductive LaAlO3/SrTiO3 is a well-known oxide interface that exhibits a variety of interesting phenomena, such as superconductivity, magnetism, and spin-orbit interactions. These electronic properties are spatially modulated over bulk SrTiO3 domain structures, due to the cubic-to-tetragonal structural transition at 105K. The system therefore offers a unique platform for investigating the coupling between orders (charge, ferroelastic, and maybe ferroelectric) that are modulated over the structural domains. However, the mechanism of such conductivity modulations is unknown, as well as whether the ferroelastic domains or domain walls dominate the behavior. In this study, we use scanning superconducting interference device (SQUID) to spatially map current modulations in a (111)-oriented LaAlO3/SrTiO3 interface. I will demonstrate how we identify the various domains and discuss the origin of this behavior.