Negative magnetoresistance in quantum-dot spin valve in cotunneling regime

Shogo Naya, Mikio Eto

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The transport through a quantum-dot spin valve is theoretically examined when an electron spin 1/2 is localized in the quantum dot by the Coulomb blockade. The cotunneling current by the second-order tunnel processes is evaluated. We show that spin-flip cotunneling processes result in a negative magnetoresistance, which means that the conductance is larger in the antiparallel (AP) alignment of the magnetization in the ferromagnets than in the parallel (P) alignment, when double tunnel barriers are largely asymmetric. In the presence of Zeeman splitting in the quantum dot, the differential conductance can show a larger peak in the AP alignment when the bias voltage is matched to the splitting.

Original languageEnglish
Title of host publicationPhysics of Semiconductors - 30th International Conference on the Physics of Semiconductors, ICPS-30
Pages687-688
Number of pages2
DOIs
Publication statusPublished - 2011
Event30th International Conference on the Physics of Semiconductors, ICPS-30 - Seoul, Korea, Republic of
Duration: 2010 Jul 252010 Jul 30

Publication series

NameAIP Conference Proceedings
Volume1399
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Other

Other30th International Conference on the Physics of Semiconductors, ICPS-30
Country/TerritoryKorea, Republic of
CitySeoul
Period10/7/2510/7/30

Keywords

  • Coulomb blockade
  • cotunneling
  • quantum dot
  • spin valve

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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