Change of microscopic tunneling on a macroscopic time scale: Current surge model

The current surge model is proposed to calculate the tunneling current in multiple quantum well structures in the presence of a slow time-dependent electric field. The microscopic origin of a zero-bias residual current observed and reported previously [A. Singh and D. A. Cardimona, Opt. Eng. (Bellingham) 38, 1424 (1999)] is explored. The mystery of the observation of a microscopic tunneling change on a macroscopic time scale is uncovered, and an involvement of a very slow physical process is shown. Some new features, such as a current "ripple," a current instability, a current hysteresis, and a current "arch," are predicted and confirmed experimentally. (C) 2000 American Institute of Physics. [S0021-8979(00)01205-6].