Ionic Liquid Gating of SrTiO3 Nanowires

In recent years, ionic liquid (IL) field effect gating of complex oxides has revealed novel electronic phases in electronic density regimes not easily attainable by chemical doping or by solid gate dielectric field effect tuning. Specifically, ionic liquid gated Strontium Titanate (STO) serves as an ideal system to study due to its relevance to the LaAlO3/SrTiO3 hetero-interface. Nevertheless, IL gating of nanoscale regions of STO has not been extensively explored. In this talk, the results of IL gated nanowires of STO will be discussed. Nanowires, patterned by electron beam lithography, are defined by a narrow channel of width 100nm in the resist PMMA on top of single crystal STO substrates. The IL is confined to this channel and thus by applying a gate voltage will accumulate electrons at the IL/STO interface, i.e. at the channel floor, by the formation on an electric double layer. Non-linear current-voltage characteristics have been observed using a two-terminal geometry over a set of gate voltages and a temperature range of 2K-35K. These characteristics exhibit behavior similar to Coulomb Blockade physics; however, the possibility of other phenomena has not been ruled out.