Scientific Reports (Apr 2022)

Hysteretic temperature dependence of resistance controlled by gate voltage in LaAlO3/SrTiO3 heterointerface electron system

  • Yongsu Kwak,
  • Woojoo Han,
  • Joon Sung Lee,
  • Jonghyun Song,
  • Jinhee Kim

DOI
https://doi.org/10.1038/s41598-022-10425-3
Journal volume & issue
Vol. 12, no. 1
pp. 1 – 7

Abstract

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Abstract For two-dimensional electron gas device applications, it is important to understand how electrical-transport properties are controlled by gate voltage. Here, we report gate voltage-controllable hysteresis in the resistance–temperature characteristics of two-dimensional electron gas at LaAlO3/SrTiO3 heterointerface. Electron channels made of the LaAlO3/SrTiO3 heterointerface showed hysteretic resistance–temperature behavior: the measured resistance was significantly higher during upward temperature sweeps in thermal cycling tests. Such hysteretic behavior was observed only after application of positive back-gate voltages below 50 K in the thermal cycle, and the magnitude of hysteresis increased with the applied back-gate voltage. To explain this gate-controlled resistance hysteresis, we propose a mechanism based on electron trapping at impurity sites, in conjunction with the strong temperature-dependent dielectric constant of the SrTiO3 substrate. Our model explains well the observed gate-controlled hysteresis of the resistance–temperature characteristics, and the mechanism should be also applicable to other SrTiO3-based oxide systems, paving the way to applications of oxide heterostructures to electronic devices.