Landau–Floquet modulation of ballistic thermionic emission in a driven electron gas

We propose a theoretical model for a two-terminal ballistic thermionic device in which the left electrode is subjected to a static magnetic field and a THz driving field, while the right electrode is treated as an ordinary parabolic thermionic emitter. By incorporating the Landau–Floquet spectral coefficient derived from a driven three-dimensional electron gas, we show that the left-to-right thermionic emission can be strongly suppressed through coherent redistribution of the emitting-channel weights. This suppression window can reverse the two-terminal net current, with its width tunable by the THz driving amplitude and its overall emission strength controlled by temperature and barrier height. Based on the output power and the heat currents extracted from the two electrodes, we identify generator-like, cooling, and reverse-current working regimes. Our results suggest a cyclotron-resonance-driven spectral-redistribution mechanism for controlling thermionic working modes in tunable thermionic energy-conversion devices.