Transient analysis of ballistic transport in stublike quantum waveguides

Switching properties of a T-shaped quantum waveguide are studied by solving the two-dimensional time-dependent Schrodinger equation under continuous injection. Assuming a ballistic electron transport, the conductance transient alternately overshoots and undershoots the steady-state value and shows a self-sustaining harmonic oscillation in the long-time limit. Analysis by Fourier transform resolves the various spectral contributions in the terahertz range and it is found that the quantum system keeps a memory of its initial state at short times. Pronounced mixing effects are shown with an electron wave function shared between the bound and metastables states of the initial and final eigenspectra. (C) 1997 American Institute of Physics.