Ion-Liquid-Gated KTaO3-Based Electric Double Layer Transistor

The electric double layer transistor (EDLT) based on the two-dimensional electron gases (2DEGs) at the LaAlO
$_{\mathbf {{3}}}$
/KTaO
$_{\mathbf {{3}}}$
(LAO/KTO) interface is fabricated. Using the ionic liquid gating (ILG), we increase the carrier density of 2DEGs from
$2.49\times 10^{\mathbf {{13}}}$
to
$4.37\times 10^{\mathbf {{13}}}$
cm
$^{\mathbf {-{2}}}$
and Hall mobility from 140 to 229 cm
$^{\mathbf {{2}}}\,\,\cdot \,\,\text{V}^{\mathbf {-{1}}}\,\,\cdot \,\,\text{s}^{\mathbf {-{1}}}$
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
$3.08\times 10^{\mathbf {{13}}}$
cm
$^{\mathbf {-{2}}}$
. 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.