Self-Gating Effect in the Electron Y-Branch Switch

In an electron waveguide Y-branch switch the electrostatic field applied between two gates switches a current into either of two branches. A novel mode of operation is proposed. For finite source-drain potentials, the switching field is shown to be strongly influenced by the electrochemical potentials in the waveguides. For certain biasing schemes this can be used to achieve gain without external gates and their RC constants. This allows switching up into the THz range in this new class of gateless mesoscopic devices. Conditions for bistability and oscillation are derived.