Ion-Liquid-Gated KTaO <sub>3</sub> -Based Electric Double Layer Transistor
Chong Zhang, Xu Zhang, Ruijie Xu, Ruxin Liu, Wei Niu, Rongzheng Gao, Anke Song, Wenzhuo Zhuang, Zhong‐Qiang Chen, Rong Zhang, Xuefeng Wang
Abstract
The electric double layer transistor (EDLT) based on the two-dimensional electron gases (2DEGs) at the LaAlO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathbf {{3}}}$ </tex-math></inline-formula> /KTaO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathbf {{3}}}$ </tex-math></inline-formula> (LAO/KTO) interface is fabricated. Using the ionic liquid gating (ILG), we increase the carrier density of 2DEGs from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.49\times 10^{\mathbf {{13}}}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.37\times 10^{\mathbf {{13}}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathbf {-{2}}}$ </tex-math></inline-formula> and Hall mobility from 140 to 229 cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathbf {{2}}}\,\,\cdot \,\,\text{V}^{\mathbf {-{1}}}\,\,\cdot \,\,\text{s}^{\mathbf {-{1}}}$ </tex-math></inline-formula> at 5 K by sweeping gate voltage from −2.5 to 3 V. Meanwhile, the gate-tunable Kondo effect is observed once the carrier density at 5 K is lower than the critical value of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.08\times 10^{\mathbf {{13}}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathbf {-{2}}}$ </tex-math></inline-formula> . Notably, the Rashba spin-orbit coupling of 2DEGs is further regulated by the ILG with the largest spin-splitting energy of 25.42 meV. These results suggest that the ILG serves as a powerful technique to explore the unprecedented properties of KTO-based 2DEGs and design the EDLT devices with superior performances.