Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3 Interface

Abstract

The oxide heterostructure LaAlO3/SrTiO3 supports a two-dimensional electron liquid with a variety of competing phases including magnetism, superconductivity and weak antilocalization due to Rashba spin-orbit coupling. Further confinement of this 2D electron liquid to the quasi-one-dimensional regime can provide insight into the underlying physics of this system and reveal new behavior. Here we describe magnetotransport experiments on narrow LaAlO3/SrTiO3 structures created by a conductive atomic force microscope lithography technique. Four-terminal local transport measurements on ~10-nm-wide Hall bar structures yield longitudinal resistances that are comparable to the resistance quantum h/e2 and independent of the channel length. Large nonlocal resistances (as large as 10^4 ohms) are observed in some but not all structures with separations between current and voltage that are large compared to the 2D mean-free path. The nonlocal transport is strongly suppressed by the onset of superconductivity below ~200 mK. The origin of these anomalous transport signatures is not understood, but may arise from coherent transport defined by strong spin-orbit coupling and/or magnetic interactions.

References in corpus (8)

• Magnetic effects at the interface between nonmagnetic oxides
• Direct electronic measurement of the spin Hall effect
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Nonlocal edge state transport in the quantum spin Hall state
• Topological Anderson Insulator
• Giant Nonlocality near the Dirac Point in Graphene
• Rashba induced magnetoconductance oscillations in the LaAlO3-SrTiO3 heterostructure
• Magnetic and Superconducting Ordering at LaAlO3/SrTiO3 Interfaces

Cited by in corpus (1)

• Anomalous magnetic ground state in LaAlO3/SrTiO3 interface probed by transport through nanowires