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 language | English |
|---|---|
| Article number | 235316 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 74 |
| Issue number | 23 |
| DOIs | |
| Publication status | Published - 2006 Dec 20 |
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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 journal › Article
}
TY - JOUR
T1 - Magnetoresistance of a quantum dot with spin-active interfaces
AU - Cottet, Audrey
AU - Choi, Mahn-Soo
PY - 2006/12/20
Y1 - 2006/12/20
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevB.74.235316
DO - 10.1103/PhysRevB.74.235316
M3 - Article
VL - 74
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 23
M1 - 235316
ER -