Graphene plasmonic emission by quantum Čerenkov effect in confined structures: Magnetic field control and tunability

We study the quantum Čerenkov effect as a mechanism for low-THz amplification in graphene monolayers confined between metallic electrodes. The confined structure linearizes the plasmon dispersion and enhances emission rates by an order of magnitude compared to unconfined configurations. We extend the theoretical framework by introducing a transverse static magnetic field, which induces Landau level quantization and magnetoplasmon formation. The magnetic field enables directional control of emission, enhances emission rates through resonant inter-Landau transitions, extends the operational frequency range, and introduces non-reciprocal behavior. These findings demonstrate magnetically tunable THz sources with integrated control of emission direction, frequency, and polarization, opening pathways for advanced THz amplifiers and integrated photonic devices.