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.
@article{arxiv.1303.1079,
title = {Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3 Interface},
author = {Guanglei Cheng and Joshua P. Veazey and Patrick Irvin and Cheng Cen1 and Daniela F. Bogorin1 and Feng Bi and Mengchen Huang and Shicheng Lu and Chung-Wung Bark and Sangwoo Ryu and Kwang-Hwan Cho and Chang-Beom Eom and Jeremy Levy},
journal= {arXiv preprint arXiv:1303.1079},
year = {2013}
}