TRANSIENT ANALYSIS OF BALLISTIC TRANSPORT IN STUBLIKE QUANTUM WAVE-GUIDES

Switching properties of a T-shaped quantum waveguide are studied by so lving the two-dimensional time-dependent Schrodinger equation under co ntinuous injection. Assuming a ballistic electron transport, the condu ctance transient alternately overshoots and undershoots the steady-sta te value and shows a self-sustaining harmonic oscillation in the long- time limit. Analysis by Fourier transform resolves the various spectra l contributions in the terahertz range and it is found that the quantu m system keeps a memory of its initial state at short times. Pronounce d mixing effects are shown with an electron wave function shared betwe en the bound and metastables states of the initial and final eigenspec tra. (C) 1997 American Institute of Physics.