Generalized multi-terminal decoherent transport: recursive algorithms and applications to SASER and giant magnetoresistance

CARLOS CATTENA; LUCAS J. FERNÁNDEZ; RAÚL BUSTOS-MARÚN; DAIJIRO NOZAKI; HORACIO M. PASTAWSKI

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Lugar: Londres; Año: 2014 vol. 26 p. 345304 - 345318

0953-8984

Decoherent transport in mesoscopic and nanoscopic systems can be formulated in terms of theD'Amato-Pastawski (DP) model. This generalizes the Landauer-Büttiker picture byconsidering a distribution of local decoherent processes. However, its generalization formulti-terminal set-ups is lacking. We first review the original two-terminal DP model fordecoherent transport. Then, we extend it to a matrix formulation capable of dealing withmulti-terminal problems. We also introduce recursive algorithms to evaluate the Green'sfunctions for general banded Hamiltonians as well as local density of states, effectiveconductances and voltage profiles. We finally illustrate the method by analyzing two problemsof current relevance. (1) Assessing the role of decoherence in a model for phonon lasers(SASER). (2) Obtaining the classical limit of giant magnetoresistance from a spin-dependentHamiltonian. The presented methods should pave the way for computationally demandingcalculations of transport through nanodevices, bridging the gap between fully coherentquantum schemes and semiclassical ones.