Tunneling currents in mesoscopic rings
Persistent currents and currents circulating along an imperfect mesoscopic ring threaded by an external magnetic field are investigated. We study the effect of the Coulomb interaction on a ring with a double-barrier structure within it for two situations: an isolated ring and a ring connected to two...
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| Autores principales: | , , |
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| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00381101_v40_n1-8_p209_Chiappe |
| Aporte de: |
| Sumario: | Persistent currents and currents circulating along an imperfect mesoscopic ring threaded by an external magnetic field are investigated. We study the effect of the Coulomb interaction on a ring with a double-barrier structure within it for two situations: an isolated ring and a ring connected to two reservoirs at different chemical potentials. For the case of the isolated ring the magnetic flux plays the role of the electric field in the standard mesoscopic heterostructures. For the isolated ring the ground state is obtained using a Lanczos algorithm. The persistent current, the total spin of the ground state and the charge distribution are calculated. The current exhibits a bistable behavior. The Coulomb blockade is, to some extent, masked by the Kondo effect. For the ring connected to leads, the presence of the double-barrier structure modifies substantially the interference phenomena shown by perfect rings due to the Bohm-Aharonov effect. The behavior of the current as a function of the magnetic flux is also affected by the Kondo effect. |
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