https://doi.org/10.1140/epjb/e2015-60029-2
Regular Article
Scaling analysis for Aharonov-Bohm ring with an embedded quantum dot connected with ferromagnetic leads
Department of Complex and Intelligent Systems, School of Systems
Information Science, Future University Hakodate, 041-8655
Hakodate,
Japan
a
e-mail: satoshi@fun.ac.jp
Received: 12 January 2015
Received in final form: 17 March 2015
Published online: 4 May 2015
In this study, we consider the Kondo temperature and differential conductance for an Aharonov-Bohm ring with an embedded quantum dot connected with noncollinear ferromagnetic leads. Starting from the tight-binding model, we propose an equivalent Anderson model, in which the density of states depends on the Aharonov-Bohm phase. By applying the poor man’s scaling approach to the Hamiltonian, we derive the dependences of the Kondo temperature and differential conductance on the Aharonov-Bohm phase, spin polarization, angle of magnetic moment, and asymmetry parameters. We show conditions for the nonmonotonic behavior of the differential conductance in terms of the spin splitting and Aharonov-Bohm phase. In addition, by extending the model to the case of a finite ring size, we show that the Kondo temperature crucially depends on ring size, but the properties of the scaled temperature are similar to ones for the small ring-size limit.
Key words: Mesoscopic and Nanoscale Systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2015