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Title: Tunnel magnetoresistance and linear conductance of double quantum dots strongly coupled to ferromagnetic leads

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4907329· OSTI ID:22410091
 [1]
  1. Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań (Poland)

We analyze the spin-dependent linear-response transport properties of double quantum dots strongly coupled to external ferromagnetic leads. By using the numerical renormalization group method, we determine the dependence of the linear conductance and tunnel magnetoresistance on the degree of spin polarization of the leads and the position of the double dot levels. We focus on the transport regime where the system exhibits the SU(4) Kondo effect. It is shown that the presence of ferromagnets generally leads the suppression of the linear conductance due to the presence of an exchange field. Moreover, the exchange field gives rise to a transition from the SU(4) to the orbital SU(2) Kondo effect. We also analyze the dependence of the tunnel magnetoresistance on the double dot levels' positions and show that it exhibits a very nontrivial behavior.

OSTI ID:
22410091
Journal Information:
Journal of Applied Physics, Vol. 117, Issue 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English