# Electrostatic tuning of magnetism at the conducting (111) (La$_{0.3}$Sr$_{0.7}$)(Al$_{0.65}$Ta$_{0.35}$)/SrTiO$_3$ interface

## TL;DR

This study investigates how applying a back gate voltage influences the electrical transport and magnetic properties of a two-dimensional electron gas at a specific oxide interface, revealing the interplay between electrostatic tuning and emergent magnetism.

## Contribution

It demonstrates the correlation between gate voltage, carrier type, and magnetic ordering at the (111) LSAT/STO interface, providing new insights into electrostatic control of magnetism in oxide interfaces.

## Key findings

- Reduction in Hall coefficient magnitude below 20 V indicating hole carriers
- Transition from nonhysteretic to hysteretic magnetoresistance at low temperatures
- Gate voltage influences magnetic order onset

## Abstract

We present measurements of the low temperature electrical transport properties of the two dimensional carrier gas that forms at the interface of $(111)$ (La$_{0.3}$Sr$_{0.7}$)(Al$_{0.65}$Ta$_{0.35}$)/SrTiO$_3$ (LSAT/STO) as a function of applied back gate voltage, $V_g$. As is found in (111) LaAlO$_3$/SrTiO$_3$ interfaces, the low-field Hall coefficient is electron-like, but shows a sharp reduction in magnitude below $V_g \sim$ 20 V, indicating the presence of hole-like carriers in the system. This same value of $V_g$ correlates approximately with the gate voltage below which the magnetoresistance evolves from nonhysteretic to hysteretic behavior at millikelvin temperatures, signaling the onset of magnetic order in the system. We believe our results can provide insight into the mechanism of magnetism in SrTiO$_3$ based systems.