Reconfigurable Oxide Nanoelectronics by Tip-induced Electron Delocalization

TL;DR

This paper introduces a vacuum-compatible, cryogenic reconfigurable oxide nanoelectronic device fabrication method using tip-induced oxygen vacancy engineering, enabling quantum regime control at millikelvin temperatures.

Contribution

It presents a waterless cAFM lithography technique for oxide interfaces, allowing nonvolatile, reconfigurable control of quantum phases at mK temperatures with high precision.

Findings

Achieved nanoscale interfacial polaron-electron liquid transition control at 0.85 nm resolution.

Demonstrated vacuum and cryogenic compatible oxide device reconfiguration.

Supported by first-principles calculations and drift-diffusion modeling.

Abstract

Reconfigurable oxide nanoelectronics, enabled by conductive atomic force microscope (cAFM) lithography, have established complex oxide interfaces as a promising platform for quantum engineering that harnesses emergent phenomena for advanced functionalities. However, this cAFM nanofabrication process can only occur in the air, with simultaneous device decay described under the "water-cycle" writing mechanism. These restrictions pose ongoing challenges for device optimization in the quantum regime at mK temperatures. Here, we demonstrate a "waterless" cAFM lithography approach that is compatible with vacuum and cryogenic environments. Through oxygen vacancy engineering at the LaAlO$_3$/SrTiO$_3$ interface, we have achieved nonvolatile and reconfigurable cAFM control of nanoscale interfacial polaron-electron liquid transition at mK temperatures with an ultrafine line resolution of 0.85 nm. Supported by first-principles calculations and drift-diffusion modeling, we show that tip-controlled oxygen vacancy electromigration plays a key role. This advancement bridges reconfigurable device fabrication and concurrent characterization in situ at mK temperatures, and establishes a versatile Hubbard toolbox for engineering programmable quantum phases in correlated oxides.