Electric field control of SrVO3 double quantum well

Field-effect transistors are widely used to control carrier density in a channel of a semiconductor by a gate voltage. Mott transistors employing strongly correlated electron systems as a channel are particularly intriguing due to their switching mechanism being cooperative phase transitions. In contrast to conventional approach of modulating carrier density or filling in a Mott insulator, we propose an alternative approach of tuning effective bandwidth. We employ SrVO3 double quantum well (DQW) channel, where metal–insulator transition is induced by gate-controlling the tunneling probability of the localized V 3d electrons between two QWs. In contrast to conventional unipolar accumulation/depletion responses in single QW channels, DQW exhibits conductance suppression in both of positive and negative gate voltages. The observed switching behavior can be ascribed to the misalignment of quantized energy levels, suppressing the resonant tunneling effect and enhancing electron correlations.