Spin filtering and thermopower in star-coupled quantum dot devices
We analyze the linear thermoelectric transport properties of devices with three quantum dots in a star configuration. A central quantum dot is tunnel-coupled to source and drain electrodes and to two additional quantum dots. For a wide range of parameters, in the absence of an external magnetic fiel...
| Autores: | , |
|---|---|
| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2016 |
| País: | Argentina |
| Recursos: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositório: | CONICET Digital (CONICET) |
| Idioma: | inglês |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/48653 |
| Acesso em linha: | http://hdl.handle.net/11336/48653 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Thermopower Electronic Kondo https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Resumo: | We analyze the linear thermoelectric transport properties of devices with three quantum dots in a star configuration. A central quantum dot is tunnel-coupled to source and drain electrodes and to two additional quantum dots. For a wide range of parameters, in the absence of an external magnetic field, the system is a singular Fermi liquid with a nonanalytic behavior of the electric transport properties at low energies. The singular behavior is associated with the development of a ferromagnetic or an underscreened Kondo effect, depending on the parameter regime. A magnetic field drives the system into a regular Fermi liquid regime and leads to a large peak (∼kB/|e|) in the spin thermopower as a function of the temperature, and to a ∼100% spin polarized current for a wide range of parameters due to interference effects. We find a qualitatively equivalent behavior for systems with a larger number of side-coupled quantum dots, with the maximum value of the spin thermopower decreasing as the number of side-coupled quantum dots increases. |
|---|