Electromagnetic interactions in quantum Hall ferromagnets
- Laboratoire de Physique Nucleaire, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada)
The {nu}=1 quantum Hall ground state in materials like GaAs is known to be ferromagnetic in nature. The exchange part of the Coulomb interaction provides the required attractive force to align the electronic spins spontaneously. The gapless Goldstone modes are the angular deviations of the magnetization vector from its fixed ground state orientation. Furthermore, the system supports electrically charged spin skyrmion configurations. It has been claimed in the literature that these skyrmions have half-integral spin owing to the presence of a topological Hopf term in the effective action governing the spin excitations. However, it has also been claimed that the derivation leading to this term is somewhat flawed. In this article, we demonstrate the existence of this term unambiguously. Furthermore, we investigate the electromagnetic interactions of the spin excitations and obtain a compact expression for the leading nonminimal electromagnetic coupling of these degrees of freedom.
- OSTI ID:
- 21202427
- Journal Information:
- AIP Conference Proceedings, Vol. 452, Issue 1; Conference: 20. annual meeting of the Montreal-Rochester-Syracuse-Toronto (MRST) conference on high energy physics: Toward the theory of everything, Montreal, PQ (Canada), 13-15 May 1998; Other Information: DOI: 10.1063/1.57071; (c) 1998 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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