Delay time of electron wave packet through a two-dimensional semiconductor heterostructure
Department of Physics, Shanghai University, 99 Shangda Road, Shanghai, 200444, P.R. China
2 State Key Laboratory of Transient Optics and Photonics, Xian Institute of Optics and Precision Mechanics of CAS, Xian, 710119, P.R. China
Revised: 3 February 2008
Published online: 8 May 2008
In this work, we systematically investigate the group delay time of an electron wave packet through a two-dimensional semiconductor heterostructure. It is shown that the lateral displacement, resulting from the angular spread of the electron wave packet, plays an important role in total delay time. In the propagating case, the group delay time can be negative due to the effect of lateral displacement, and is greatly enhanced by transmission resonances. In the evanescent case, the delay time saturates to a constant in the opaque limit, which is simply the Hartman effect observed for a two-dimensional situation.
PACS: 03.65.Xp – Tunneling, traversal time, quantum Zeno dynamics / 73.23.-b – Electronic transport in mesoscopic systems / 03.65.-w – Quantum mechanics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008