Antiresonant hopping conductance and negative magnetoresistance in quantum-box superlattices

Electric current in a one-dimensional chain of quantum boxes is characterized by a set of zero minima (antiresonances) due to the momentum selection rule for the interaction of acoustic phonons with Wannier-Stark localized electrons or due to the folded phonon gaps. Antiresonances manifest also in the conduction of superlattices in the presence of an external source of phonons. Negative magnetoresistance of superlattices in high electric fields is predicted. We also clarify general questions of boundary conditions in the hopping regime.