English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/7315
COMPARTIR / IMPACTO:
Estadísticas
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:
Título

A time-dependent approach to electron pumping in open quantum systems

AutorStefanucci, Gianluca; Kurth, S.; Rubio, Angel; Gross, E. K. U.
Palabras claveBound states
Density functional theory
Electron density
Electron transport theory
Fecha de publicación29-feb-2008
EditorAmerican Physical Society
CitaciónPhysical Review B 77: 75339 (2008)
ResumenWe use a recently proposed time-dependent approach to investigate the motion of electrons in quantum pump device configurations. The occupied one-particle states are propagated in real time and employed to calculate the local electron density and current. The approach can also be embedded in the framework of time-dependent density functional theory to include electron-electron interactions. An advantage of the present computational scheme is that the same computational effort is required to simulate monochromatic, polychromatic, and nonperiodic drivings. Furthermore, initial-state dependence and history effects are naturally accounted for. We present results for one-dimensional devices exposed to a traveling potential wave. (i) We show that for pumping across a single potential barrier, electrons are transported in pockets and the transport mechanism resembles pumping of water with the Archimedean screw; (ii) we propose a simple model to study pumping through semiconductor nanostructures and we address the phenomenon of the current flowing in the opposite direction to the field propagation; (iii) we present the first numerical evidence of long-lived superimposed oscillations as induced by the presence of bound states and discuss the dependence of their lifetime on the frequency and amplitude of the driving field. By combining Floquet theory with nonequilibrium Green's functions, we also obtain a general expression for the pumped current in terms of inelastic transmission probabilities. This latter result is used for benchmarking our propagation scheme in the long-time limit. Finally, we discuss the limitations of Floquet-based algorithms and suggest our approach as a possible way to go beyond them.
DescripciónPACS nrs.: 73.23.-b, 05.60.Gg, 72.10.-d, 73.63.-b
Versión del editorhttp://dx.doi.org/10.1103/PhysRevB.77.075339
URIhttp://hdl.handle.net/10261/7315
DOI10.1103/PhysRevB.77.075339
ISSN1098-0121
Aparece en las colecciones: (CFM) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
time-dependent approach.pdf587,67 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.