Gardner 9706792 The propagation of electrons in quantum semiconductor devices (e.g. resonant tunneling diodes, superlattices, and HEMT and MODFET transistors) can be modeled as the flow of a continuous charged quantum gas in a potential that has discontinuous jumps at heterojunction barriers. Quantum fluid dynamical equations can be derived by assuming the gas is near thermal equilibrium, but are expected to be more generally valid. The investigator and his colleague focus on theoretical modeling, simulation, and analysis of the flow of electrons in one and two spatial dimensions in quantum semiconductor devices based on the ``smooth'' quantum hydrodynamic model and quantum kinetic equations (including the Bloch equation and the Wigner-Boltzmann equation). The development of modern upwind numerical methods for simulating these equations on high performance computers is emphasized. Semiconductor devices --- like resonant tunneling diodes and transistors --- 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. The investigators model the behavior of quantum semiconductor devices by treating electron flow by means of quantum hydrodynamic and quantum kinetic equations. The models and numerical methods are implemented in a high-performance industrial computer program that can be used by the semiconductor manufacturing industry. In this way, semiconductor design engineers can efficiently explore the behavior of various device materials and structures on the computer before actually fabricating the semiconductor device.
