publication . Preprint . Article . 2009

Ferromagnetic Spin Coupling as the Origin of 0.7 Anomaly in Quantum Point Contacts

Jong E. Han; Karan Aryanpour;
Open Access English
  • Published: 05 Feb 2009
Abstract
We study one-dimensional itinerant electron models with ferromagnetic coupling to investigate the origin of 0.7 anomaly in quantum point contacts. Linear conductance calculations from the quantum Monte Carlo technique for spin interactions of different spatial range suggest that $0.7(2e^{2}/h)$ anomaly results from a strong interaction of low-density conduction electrons to ferromagnetic fluctuations formed across the potential barrier. The conductance plateau appears due to the strong incoherent scattering at high temperature when the electron traversal time matches the time scale of dynamic ferromagnetic excitations.
Subjects
arXiv: Condensed Matter::Strongly Correlated Electrons
free text keywords: Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Strongly Correlated Electrons, General Physics and Astronomy, Quantum spin liquid, Spin-½, Quantum point contact, Electron, Quantum Monte Carlo, Incoherent scatter, Rectangular potential barrier, Condensed matter physics, Physics, Conductance quantum
Funded by
NSF| ITR: Advances of Simulation Algorithm of Quantum Manybody Transport in Steady State Nonequilibrium
Project
  • Funder: National Science Foundation (NSF)
  • Project Code: 0426826
  • Funding stream: Directorate for Mathematical & Physical Sciences | Division of Materials Research
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