Transient Schrödinger-Poisson Simulations of a High-Frequency Resonant Tunneling Diode Oscillator
This work provides a computational method for simulating high-frequency resonant tunneling diode oscillators, which is important for device design but represents an incremental advance in numerical techniques.
The authors present transient simulations of a resonant tunneling diode oscillator using a Schrödinger-Poisson model with transparent boundary conditions, achieving the first simulation of self-oscillatory behavior in such a circuit.
Transient simulations of a resonant tunneling diode oscillator are presented. The semiconductor model for the diode consists of a set of time-dependent Schrödinger equations coupled to the Poisson equation for the electric potential. The one-dimensional Schrödinger equations are discretized by the finite-difference Crank-Nicolson scheme using memory-type transparent boundary conditions which model the injection of electrons from the reservoirs. This scheme is unconditionally stable and reflection-free at the boundary. An efficient recursive algorithm due to Arnold, Ehrhardt, and Sofronov is used to implement the transparent boundary conditions, enabling simulations which involve a very large number of time steps. Special care has been taken to provide a discretization of the boundary data which is completely compatible with the underlying finite-difference scheme. The transient regime between two stationary states and the self-oscillatory behavior of an oscillator circuit, containing a resonant tunneling diode, is simulated for the first time.