Theory of magnetic structure determination for small ferromagnets

Mihai Preda, Stewart Barnes

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

An easy plane ferromagnetic nanoparticle with a magnetic field along the easy axis in the easy plane, is considered. When the applied field is reversed the system finds itself in a metastable ground state of a double well potential. Tunneling is between this state and the various states on the other, stable, side of the double well. Unlike the much studied case of Mn12, the states into which the system tunnels have energies determined by harmonic oscillations about equilibrium. Specific expressions are obtained for the tunneling matrix elements examined between the various levels and for relaxation toward the ground state. The formalism involves auxiliary particle techniques and the results are contrasted with the existing theory based upon the functional integral approach.

Original languageEnglish (US)
Pages (from-to)5630-5632
Number of pages3
JournalJournal of Applied Physics
Volume85
Issue number8 II B
StatePublished - Apr 15 1999

Fingerprint

harmonic oscillation
ground state
tunnels
formalism
nanoparticles
matrices
magnetic fields
energy

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physics and Astronomy (miscellaneous)

Cite this

Theory of magnetic structure determination for small ferromagnets. / Preda, Mihai; Barnes, Stewart.

In: Journal of Applied Physics, Vol. 85, No. 8 II B, 15.04.1999, p. 5630-5632.

Research output: Contribution to journalArticle

@article{281eef4439de46d3b299a955649330b7,
title = "Theory of magnetic structure determination for small ferromagnets",
abstract = "An easy plane ferromagnetic nanoparticle with a magnetic field along the easy axis in the easy plane, is considered. When the applied field is reversed the system finds itself in a metastable ground state of a double well potential. Tunneling is between this state and the various states on the other, stable, side of the double well. Unlike the much studied case of Mn12, the states into which the system tunnels have energies determined by harmonic oscillations about equilibrium. Specific expressions are obtained for the tunneling matrix elements examined between the various levels and for relaxation toward the ground state. The formalism involves auxiliary particle techniques and the results are contrasted with the existing theory based upon the functional integral approach.",
author = "Mihai Preda and Stewart Barnes",
year = "1999",
month = "4",
day = "15",
language = "English (US)",
volume = "85",
pages = "5630--5632",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "8 II B",

}

TY - JOUR

T1 - Theory of magnetic structure determination for small ferromagnets

AU - Preda, Mihai

AU - Barnes, Stewart

PY - 1999/4/15

Y1 - 1999/4/15

N2 - An easy plane ferromagnetic nanoparticle with a magnetic field along the easy axis in the easy plane, is considered. When the applied field is reversed the system finds itself in a metastable ground state of a double well potential. Tunneling is between this state and the various states on the other, stable, side of the double well. Unlike the much studied case of Mn12, the states into which the system tunnels have energies determined by harmonic oscillations about equilibrium. Specific expressions are obtained for the tunneling matrix elements examined between the various levels and for relaxation toward the ground state. The formalism involves auxiliary particle techniques and the results are contrasted with the existing theory based upon the functional integral approach.

AB - An easy plane ferromagnetic nanoparticle with a magnetic field along the easy axis in the easy plane, is considered. When the applied field is reversed the system finds itself in a metastable ground state of a double well potential. Tunneling is between this state and the various states on the other, stable, side of the double well. Unlike the much studied case of Mn12, the states into which the system tunnels have energies determined by harmonic oscillations about equilibrium. Specific expressions are obtained for the tunneling matrix elements examined between the various levels and for relaxation toward the ground state. The formalism involves auxiliary particle techniques and the results are contrasted with the existing theory based upon the functional integral approach.

UR - http://www.scopus.com/inward/record.url?scp=0003056260&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0003056260&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0003056260

VL - 85

SP - 5630

EP - 5632

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 8 II B

ER -