Title: Numerical Methods for the Wigner-Poisson Equations Location: Building 980, Room 95 (Sandia NM) Brief Abstract: Resonant tunneling diodes are prototypical nanoscale semiconductor devices that theory and numerical simulation predict can develop terahertz frequency current oscillation. Since these devices are developed at such a small size, quantum physics (instead of classical physics) dictate their operation. The Wigner-Poisson equations describe quantum mechanical electron transport and are used in modeling the resonant tunneling diode. In this talk, time-dependent and time-independent simulation of the device are discussed and compared. While the time-dependent simulation can immediately detect current oscillation, it is computationally intensive to perform. In contrast, while the time-independent simulation can more quickly generate the steady-state current-voltage relationship of the device, determining if current oscillation will occur requires solving an eigenvalue problem which is also computationally expensive. To speed-up solving the eigenvalue problem, a spectral transformation, the Cayley transform, is implemented. Numerical results will be presented. CSRI POC: Eric Keiter (505) 284-6088 |