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The Influence of Many-Body Interactions on the Electron States in Quantum Point Contacs: Persistence of Exchange-Driven Splitting at High External Magnetic Fields

  • I. I. Yakimenko
  • K.-F. Berggren
Original Paper

Abstract

Spontaneous spin polarization of a quasi-1D electron gas in quantum point contacts (QPCs) is an important concept when analyzing conductance anomalies in the quantum limit. As suggested by recent measurements (Koop et al., J. Supercond. Nov. Magn. 20:433, 2007) there is a splitting of the subband levels in QPCs related to 0.7 conductance anomaly, both for zero- and finite in-plane magnetic fields. In the present paper we present theoretical results for spin polarization occurring in a QPC in a magnetic field as obtained from the local spin-density approximation (LSDA). Our numerical simulations are consistent with the findings of Koop et al. and support the idea that spin polarization underpins the conductance anomaly.

Keywords

Quantum point contacts Nanomagnetism Quantum transport 0.7 anomaly 

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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.IFMLinköping UniversityLinköpingSweden

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