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arXiv · 1807.08345

Dual-Gate Modulation of Carrier Density and Disorder in an Oxide Two-Dimensional Electron System

Zhuoyu Chen·Hongtao Yuan·Yanwu Xie·Di Lu·Hisashi Inoue·Yasuyuki Hikita·Christopher Bell·Harold Y. Hwang
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Abstract

Carrier density and disorder are two crucial parameters that control the properties of correlated two-dimensional electron systems. In order to disentangle their individual contributions to quantum phenomena, independent tuning of these two parameters is required. Here, by utilizing a hybrid liquid/solid electric dual-gate geometry acting on the conducting LaAlO3/SrTiO3 heterointerface, we obtain an additional degree of freedom to strongly modify the electron confinement profile and thus the strength of interfacial scattering, independent from the carrier density. A dual-gate controlled nonlinear Hall effect is a direct manifestation of this profile, which can be quantitatively understood by a Poisson-Schrodinger subband model. In particular, the large nonlinear dielectric response of SrTiO3 enables a very wide range of tunable density and disorder, far beyond that for conventional semiconductors. Our study provides a broad framework for understanding various reported phenomena at the LaAlO3/SrTiO3 interface.

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Zhuoyu Chen, Hongtao Yuan, Yanwu Xie, Di Lu, Hisashi Inoue, Yasuyuki Hikita, Christopher Bell, Harold Y. Hwang. 2018-07-22. Dual-Gate Modulation of Carrier Density and Disorder in an Oxide Two-Dimensional Electron System. https://doi.org/10.1021/acs.nanolett.6b02348

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