Nonequilibrium field effect and memory in the electron glass

We present an experimental study of the nonequilibrium transport in Anderson-insulating indium-oxide films. In particular, we focus on the characteristic features of the cusp that is observed in field-effect (FE) experiments around the gate voltage at which the system has equilibrated. It is shown that the shape of the cusp depends on the temperature history, as well as on the measurement temperature. On the other hand, it is insensitive to the rate and direction of the gate voltage sweeps, disorder, or magnetic field up to 20 T. We discuss a physical picture leading to the appearance of such a cusp and suggest a possible mechanism for memory in the electron-glass system. These findings demonstrate that FE experiments complement the conductance measurements and contribute to a broader perspective on the glassy dynamics.