Nonlocal effects in semiconductor nanostructure transport

A small quantum system, such as a quantum dot, can be considered to be mainly closed, in which case current flow follows by tunneling, or can be mainly open, in which case the conductance is several times 2e2/h, the quantum unit of conductance. Even in this case, however, there are trapped states within the quantum system which impact transport via phase space tunneling. When we have multiple systems, either an array of dots or of quantum point contacts, or of a combination of these, then there is the chance for a more nonlocal interaction to occur, and to affect the transport. Some of these cases are discussed in this paper.