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Volumn 47, Issue 24, 1993, Pages 16419-16426

Skyrmions and the crossover from the integer to fractional quantum Hall effect at small Zeeman energies

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Indexed keywords


EID: 0000284726     PISSN: 01631829     EISSN: None     Source Type: Journal    
DOI: 10.1103/PhysRevB.47.16419     Document Type: Article
Times cited : (1007)

References (39)
  • 1
    • 84926884469 scopus 로고    scopus 로고
    • Present address: Department of Physics, University of Illinois at Urbana Champaign, 1110 W. Green St., Urbana, Illinois 61801 3080.
  • 2
    • 84926884468 scopus 로고    scopus 로고
    • Permanent address: Department of Physics, University of Stockholm, Vanadisvägen 9, S 113,46 Stockholm, Sweden.
  • 3
    • 0003414482 scopus 로고
    • For a general introduction see, edited by, R.E. Prange, S.M. Girvin, Springer Verlag, New York
    • (1990) The Quantum Hall Effect
  • 11
    • 84926903196 scopus 로고    scopus 로고
    • Also note that as the perturbation theory is carried out at fixed ν, l/a* propto rs where rs is the radius of the area per particle in atomic units familiar from the theory of the electron gas.
  • 13
    • 84926884467 scopus 로고    scopus 로고
    • we calculate the gap as the sum of the gross quasiparticle energies.
  • 15
    • 84926922240 scopus 로고    scopus 로고
    • S.L. Sondhi, Ph.D. thesis, UCLA, 1992.
  • 17
    • 84926941181 scopus 로고    scopus 로고
    • The effect on the second order term is unknown.
  • 18
    • 84926903195 scopus 로고    scopus 로고
    • Our work here complements that of Smith, MacDonald, and Gumbs (Ref. onlinecitesmith), who have computed gaps for the integer states in a dynamic screening approximation which receives partial contributions from all orders higher than the first. They report good agreement with the data. If, as we argue below, the true quasiparticles are not perturbative quasiparticles, this agreement is at first sight fortuitous. However, as we shall see below, is likely that the true quasiparticle involves only a few extra reversed spins, so is reasonable that its creation energy is close to that of the perturbative quasiparticle.
  • 22
    • 84926941180 scopus 로고    scopus 로고
    • This conclusion was reached earlier by Haldane (see his article in Ref. onlineciteqhe) in an examination of the truncated pseudopotential models. It has also been verified by finite size and variational studies for the Coulomb interaction;
  • 24
    • 84926941179 scopus 로고    scopus 로고
    • We assume that the cyclotron gap is still larger than the Zeeman gap, i.e., we assume the ordering hbar ωc > g uB B gg e2 /l.
  • 25
    • 84926903194 scopus 로고    scopus 로고
    • The quasiparticle is of the form φ=(1,0)f where f is the familiar vortex solution of the spinless problem. The antivortex solution of this form corresponds to the quasielectron in the second Landau level. The true quasielectron corresponds to a skyrmion of size l.
  • 28
    • 84926884453 scopus 로고    scopus 로고
    • There is also a Hopf term, which is the transcription of the Chern Simons term in ( reflglag) that enforces Fermi statistics for the skyrmions, but can be ignored for our purposes.
  • 31
    • 84926884451 scopus 로고    scopus 로고
    • We have also calculated the effect of the finite extent (perpendicular to the interface) of the wave functions on the spin wave velocity, and hence on the skyrmion energy. We find that for GaAs heterojunctions, E(0) is reduced by amounts from 50,70 is unchanged; there will of course be quantitative corrections at nonzero g due to the softened interaction. In the same range of fields the energy of the microscopic (i.e., spin 1 over 2) quasiparticle is reduced by 30 $50, perturbative quasiparticle. None of these numbers includes the effects of Landau level mixing.
  • 32
    • 84926922231 scopus 로고    scopus 로고
    • By standard arguments the infinite skyrmion represents a quantum state with S=0; relative to the ground state this is an infinite spin.
  • 33
    • 84926884450 scopus 로고    scopus 로고
    • The neutral quasiparticle energies in the terminology of MacDonald and Girvin (Ref. onlinecitefn1).


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.