Thermal Activation and Quantum Field Emission in a Sketch-Based Oxide Nano Transistor

TL;DR

This paper investigates the electronic behavior of a novel sketch-based oxide nanotransistor, revealing thermally activated and quantum field emission mechanisms that are crucial for future electronic and quantum device development.

Contribution

It provides direct measurements of potential barriers and electronic coupling in a nanoscale oxide transistor, highlighting temperature-dependent emission mechanisms and structural influences.

Findings

Switching governed by thermally activated field emission near room temperature

Crossover to quantum field emission below 150 K influenced by SrTiO3 phase transitions

Measurement of energy barriers critical for device development

Abstract

The interface between polar LaAlO3 and non-polar SrTiO3 exhibits a remarkable variety of electronic behavior associated with the formation of an interfacial quasi-two-dimensional electron gas (q-2DEG). By "sketching" patterns of charge on the top LaAlO3 surface, the LaAlO3/SrTiO3 interface conductance can be controlled with near-atomic spatial resolution. Using this technique, a sketch-based oxide nanotransistor (SketchFET) was demonstrated with a minimum feature size of just two nanometers. Here we report direct measurements of the potential barriers and electronic coupling between nanowire segments within a SketchFET device. Near room temperature, switching is governed by thermally activated field emission from the nanowire gate. Below T=150 K, a crossover to quantum field emission is observed that is sensitive to structural phase transitions in the SrTiO3 layer. This direct measurement of the source-drain and gate-drain energy barriers is crucial for the development of room-temperature logic and memory elements and low-temperature quantum devices.