Broken symmetry and the formation of hot-electron domains in real-space-transfer transistors

Real-space-transfer (RST) transistors are studied theoretically. In a symmetric configuration, with no voltage applied between the channel electrodes, we find anomalous steady states in which the RST is driven by the fringing field from the collector electrode. Some of these states are unconditionally stable and hence accessible experimentally. Our study elucidates the formation of hot-electron domains, which is shown to be a discontinuous process that passes the control of electron heating from the drain to the collector. Multiply connected current-voltage characteristics are predicted.