We propose that a simple device of three laterally-coupled quantum dots, the central one contacted by metal leads, can realize the ferromagnetic Kondo model, which is characterized by interesting properties like a non-analytic inverted zero-bias anomaly and an extreme sensitivity to a magnetic field. Furthermore, by tuning the gate voltages of the lateral dots, this device may allow to study the transition from ferromagnetic to antiferromagnetic Kondo effect, a simple case of a Berezinskii-Kosterlitz-Thouless transition. We model the device by three coupled Anderson impurities that we study by numerical renormalization group. We calculate the single-particle spectral function of the central dot, which at zero frequency is proportional to the zero-bias conductance, across the transition, both in the absence and in the presence of a magnetic field.
Ferromagnetic Kondo Effect in a Triple Quantum Dot System / Baruselli, Pierpaolo; Requist, Ryan Tyler; Fabrizio, Michele; Tosatti, Erio. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 111:4(2013), pp. 047201.1-047201.5. [10.1103/PhysRevLett.111.047201]
Ferromagnetic Kondo Effect in a Triple Quantum Dot System
Baruselli, Pierpaolo;Requist, Ryan Tyler;Fabrizio, Michele;Tosatti, Erio
2013-01-01
Abstract
We propose that a simple device of three laterally-coupled quantum dots, the central one contacted by metal leads, can realize the ferromagnetic Kondo model, which is characterized by interesting properties like a non-analytic inverted zero-bias anomaly and an extreme sensitivity to a magnetic field. Furthermore, by tuning the gate voltages of the lateral dots, this device may allow to study the transition from ferromagnetic to antiferromagnetic Kondo effect, a simple case of a Berezinskii-Kosterlitz-Thouless transition. We model the device by three coupled Anderson impurities that we study by numerical renormalization group. We calculate the single-particle spectral function of the central dot, which at zero frequency is proportional to the zero-bias conductance, across the transition, both in the absence and in the presence of a magnetic field.File | Dimensione | Formato | |
---|---|---|---|
1302.1499.pdf
accesso aperto
Tipologia:
Documento in Pre-print
Licenza:
Non specificato
Dimensione
429.95 kB
Formato
Adobe PDF
|
429.95 kB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.