Magnetoresistance of a quantum dot with spin-active interfaces

Audrey Cottet, Mahn-Soo Choi

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

We study the zero-bias magnetoresistance (MR) of an interacting quantum dot connected to two ferromagnetic leads and capacitively coupled to a gate voltage source Vg. We investigate the effects of the spin-activity of the contacts between the dot and the leads by introducing an effective exchange field in an Anderson model. This spin-activity makes easier negative MR effects, and can even lead to a giant MR effect with a sign tunable with Vg. Assuming a twofold orbital degeneracy, our approach allows one to interpret in an interacting picture the MR (Vg) measured by S. Sahoo [Nature Phys. 1, 99 (2005)] in single wall carbon nanotubes with ferromagnetic contacts. If this experiment is repeated on a larger Vg range, we expect that the MR (Vg) oscillations are not regular like in the presently available data, due to Coulomb interactions.

Original languageEnglish
Article number235316
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume74
Issue number23
DOIs
Publication statusPublished - 2006 Dec 20

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Magnetoresistance
Semiconductor quantum dots
quantum dots
Giant magnetoresistance
Carbon Nanotubes
Coulomb interactions
carbon nanotubes
orbitals
Carbon nanotubes
oscillations
electric potential
Electric potential
interactions
Experiments

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Magnetoresistance of a quantum dot with spin-active interfaces. / Cottet, Audrey; Choi, Mahn-Soo.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 74, No. 23, 235316, 20.12.2006.

Research output: Contribution to journalArticle

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