Tunable Kondo effect in a double quantum dot coupled to ferromagnetic contacts

We investigate the effects induced by ferromagnetic contacts attached to a serial double quantum dot. Spin polarization generates effective magnetic fields and suppresses the Kondo effect in each dot. The superexchange interaction J(AFM), tuned by the interdot tunneling rate t, can be used to compen...

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Bibliographic Details
Published inPhysical review letters Vol. 108; no. 16; p. 166605
Main Authors Žitko, Rok, Lim, Jong Soo, López, Rosa, Martinek, Jan, Simon, Pascal
Format Journal Article
LanguageEnglish
Published United States 20.04.2012
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Summary:We investigate the effects induced by ferromagnetic contacts attached to a serial double quantum dot. Spin polarization generates effective magnetic fields and suppresses the Kondo effect in each dot. The superexchange interaction J(AFM), tuned by the interdot tunneling rate t, can be used to compensate the effective fields and restore the Kondo resonance when the contact polarizations are aligned. As a consequence, the direction of the spin conductance can be controlled and even reversed using electrostatic gates alone. Our results demonstrate a new approach for controlling spin-dependent transport in carbon nanotube double dot devices.
ISSN:1079-7114
DOI:10.1103/PhysRevLett.108.166605