Stability issues in tunneling via quantum systems

Since the introduction of resonant tunneling via man-made quantum structures, there have been concerns regarding the possibility of intrinsic instability. Some of the issues were thought to be only associated with quantum devices. In my view, the most important thing is not due to quantum effects, rather, due to a drastic reduction in the number of electrons taking part in the process. Redundancy and robustness may be established using a radically different approach.