Nanoscale channels realized at the conducting interface between LaAlO3 and SrTiO3 provide a perfect playground to explore the effect of dimensionality on the electronic properties of complex oxides. Here we compare the electric transport properties of devices realized using the AFM-writing technique and conventional photo-lithography. We find that the lateral size of the conducting paths has a strong effect on their transport behavior at low temperature. We observe a crossover from metallic to insulating regime occurring at about 50 K for channels narrower than 100 nm. The insulating upturn can be suppressed by the application of a positive backgate. We compare the behavior of nanometric constrictions in lithographically patterned channels with the result of model calculations and we conclude that the experimental observations are compatible with the physics of a quantum point contact.
@article{arxiv.2009.07867,
title = {Electronic transport in sub-micrometric channels at the LaAlO$_{3}$/SrTiO$_{3}$ interface},
author = {Margherita Boselli and Gernot Scheerer and Michele Filippone and Weiwei Luo and Adrien Waelchli and Alexey B. Kuzmenko and Stefano Gariglio and Thierry Giamarchi and Jean-Marc Triscone},
journal= {arXiv preprint arXiv:2009.07867},
year = {2021}
}