Simple Approach to Include External Resistances in the Monte Carlo Simulation of MESFET's and HEMT's - Electron Devices, IEEE Transactions on

narrower (Table I) so that the separation of energy sublevels along the y-direction is increased. This increases the oscillation period when measuring the conductances as functions of the Fermi energy. On the other hand, the increase of the Fermi energy as a function of the lower gate bias is very significant. In the final conductances versus lower gate bias diagram, Fig. 2, the Fermi energy factor dominates, and the oscillation period in the conductance increases, as indicated in the experiments when the upper gate bias is decreased. The calculated oscillation period increases with increasing lower gate bias in Fig. 2. This is due to the square-well approximation in the y-direction used in the model calculation. When parabolic well is used, the energy separations between sublevels are constant, so becomes the oscillation period. Thus, when real band profile is used in the transport calculation, constant oscillation period is expected. [4] R. Haydock, V. Heine, and M. J. Kelly, “Electronic structure based on the local atomic environment for tight-binding bands,” .I. Phys. Cc Solid Stute Phys., vol. 5, p. 2845, 1972. [SI C. S. Lent and D. J. Kirkner, “The quantum transmitting boundary method,” J. Appl. Phys., vol. 67, p. 6353, 1990. [6J Y. Wang, J. Wang, and H. Guo, “Magnetoconductance of a stadiumshaped quantum dot: A finite-element method approach,” Phys. Rev. B, vol. 49, p. 1928, 1994.