Modeling Spin Transport in Helical Fields: Derivation of an Effective Low-Dimensional Hamiltonian

This study is devoted to a consistent derivation of an effective model Hamiltonian to describe spin transport along a helical pathway and in the presence of spin-orbit interaction, the latter being induced by an external field with helical symmetry. It is found that a sizable spin polarization of an...

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Detalles Bibliográficos
Autores: Gutierrez, R., Díaz García, Elena, Gaul, Christopher, Brumme, T., Domínguez-Adame Acosta, Francisco, Cuniberti, G.
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/34750
Acceso en línea:https://hdl.handle.net/20.500.14352/34750
Access Level:acceso abierto
Palabra clave:538.9
Self-assembled monolayers
Organized organic layers
Electron transmission
Magnetic- properties
Chiral molecules
Conduction
Dna
Física de materiales
Física del estado sólido
2211 Física del Estado Sólido
Descripción
Sumario:This study is devoted to a consistent derivation of an effective model Hamiltonian to describe spin transport along a helical pathway and in the presence of spin-orbit interaction, the latter being induced by an external field with helical symmetry. It is found that a sizable spin polarization of an unpolarized incoming state can be obtained without introducing phase breaking processes. For this, at least two energy levels per lattice site in the tight-binding representation are needed. Additionally, asymmetries in the effective electronic-coupling parameters as well as in the spin-orbit interaction strength must be present to achieve net polarization. For a fully symmetric system-in terms of electronic and spin-orbit couplings-no spin polarization is found. The model presented is quite general and is expected to be of interest for the treatment of spin-dependent effects in molecular scale systems with helical symmetry.