Generation of low-frequency higher harmonics in a resonant-tunneling diode

The behavior of the higher harmonics of a resonant-tunneling diode is investigated experimentally and theoretically in the adiabatic limit. Within the framework of numerical solution of the time-dependent Schrödinger equation with open boundary conditions, the currents of the first three harmonics are calculated. It is shown that the behavior of the currents qualitatively agrees with the experimental data and the results of a simple model used by us previously. The possibility of the generation of an electromagnetic field at frequencies multiple to the harmonic number is shown.