For a parallel-plane barrier heterostructure of any form or composition, it is shown by considering the electron quantum states as functions of complex values of the energy that the full linewidth of a resonant peak in the coherent transmission probability, 2 ΔE, and the tunneling lifetime of the quasilevel giving rise to the resonance, τ, are necessarily related by (2 ΔE)τ=ħ, and the conventional wave-packet transit time is 2τ at the resonance energy. A formula is obtained for the peak transmission probability in terms of the ratio of the two outward currents for an electron escaping from the quasilevel.

• Received 11 February 1988

DOI:https://doi.org/10.1103/PhysRevB.38.1994