Title: The Smooth Quantum Hydrodynamic Model (for Semiconductor Devices)
Speaker: Professor Carl Gardner
Speaker Info: Arizona State University
Semiconductor devices--like the resonant tunneling diode--that rely on quantum tunneling are playing an increasingly important role in advanced microelectronic applications, including multiple-state logic and memory devices and high frequency oscillators. An extension of hydrodynamics to quantum mechanical electron flow will be presented that is mathematically rigorous for classical potentials with discontinuities--as are present at heterojunction barriers in quantum semiconductor devices.Date: Tuesday, December 2, 1997
The effective stress tensor in this ``smooth'' QHD model actually cancels the leading singularity in the classical potential at a barrier and leaves a residual smooth effective potential with a lower potential height in the barrier region. The smoothing makes the barrier partially transparent to the electron flow and provides the mechanism for tunneling in the QHD model. Smooth QHD simulations of resonant tunneling diodes will be presented which exhibit enhanced quantum resonance with respect to the original QHD model, and which show better agreement with experimental current-voltage curves.