Strontium titanate (SrTiO₃, STO) and potassium tantalate (KTaO₃, KTO) are insulators, quantum paraelectrics, and they both have the cubic perovskite structure at room temperature [1,2]. The charge-carrier density in these materials is usually modified via substitutional- or oxygen-vacancy doping. An alternative approach is ionic-liquid gating, which involves the use of an electric field to modify the carrier density in a material; an electric double layer forms between the sample and the ionic liquid when a gate voltage is applied between them [3]. Here we report on a systematic investigation of the gating-induced insulator-metal transition and temperature-dependent resistivity of STO and KTO.

[1] C. Collignon et al., Annual Review of Condensed Matter Physics 10, 25 (2019)

[2] K. Ueno et al., Nat. Nanotechnol. 6, 408 (2011)

[3] C. Leighton, Nat. Mater. 18, 13 (2019)

This work was supported by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-2011401.