# Collective modes of CP 3 skyrmion crystals in quantum Hall ferromagnets

@article{Ct2007CollectiveMO,
title={Collective modes of CP 3 skyrmion crystals in quantum Hall ferromagnets},
author={Ren{\'e} C{\^o}t{\'e} and D. B. Boisvert and J. Bourassa and Maxime Boissonneault and Herbert A. Fertig},
journal={Physical Review B},
year={2007},
volume={76},
pages={125320}
}
• Published 31 July 2007
• Physics
• Physical Review B
The two-dimensional electron gas (2DEG) in a bilayer quantum Hall system can sustain an interlayer coherence at filling factor $\ensuremath{\nu}=1$ even in the absence of tunneling between the layers. This system, which can be described as a quantum Hall pseudospin ferromagnet, has low-energy charged excitations which may carry textures in real spin or pseudospin. Away from filling factor $\ensuremath{\nu}=1$, a finite density of these is present in the ground state of the 2DEG and forms a…
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## References

SHOWING 1-10 OF 29 REFERENCES
Pseudospin vortex-antivortex states with interwoven spin textures in double-layer quantum Hall systems
• Physics
• 2006
Recent experiments on strongly correlated bilayer quantum Hall systems strongly suggest that, contrary to the usual assumption, the electron spin degree of freedom is not completely frozen either in
SU(4) skyrmions and activation energy anomaly in bilayer quantum Hall systems
• Physics
• 2004
The bilayer quantum Hall (QH) system has four energy levels in the lowest Landau level, corresponding to the layer and spin degrees of freedom. We investigate the system in the regime where all four
Spin-Pseudospin Coherence and C P-3 Skyrmions in Bilayer Quantum Hall Ferromagnets
We analyze bilayer quantum Hall ferromagnets, whose underlying symmetry group is SU(4). Spin-pseudospin coherence develops spontaneously when the total electron density is low enough. Quasiparticles
Interlayer exchange interactions, SU(4) soft waves, and skyrmions in bilayer quantum Hall ferromagnets
• Physics
• 2002
The exchange Coulomb interaction is the driving force for quantum coherence in quantum Hall systems. We construct a microscopic Landau-site Hamiltonian for the exchange interaction in bilayer quantum
Energy spectrum of a layered system in a strong magnetic field.
• Fertig
• Materials Science
Physical review. B, Condensed matter
• 1989
The excitation spectrum of two- and three-layer electron systems in a strong perpendicular magnetic field with 1/2 and (1/3, respectively, in each layer is investigated, indicating that the system undergoes a phase transition as the layer spacing is increased.
Skyrme and meron crystals in quantum Hall ferromagnets
• Physics
• 1996
The ground state of a two-dimensional electron gas at Landau level filling factor ν near 1 is studied in the Hartree-Fock approximation. For Zeeman coupling different from zero, the ground state is a
Spontaneous interlayer coherence in double-layer quantum Hall systems: Charged vortices and Kosterlitz-Thouless phase transitions.
• Moon, Môri
• Physics
Physical review. B, Condensed matter
• 1995
The parameters of the Landau-Ginzburg functional are obtained from first-principles estimates and from finite-size exact diagonalization studies and used to estimate the dependence of the critical temperature for the Kosterlitz-Thouless phase transition on layer separation.
Quantum-critical dynamics of the Skyrmion lattice
Near to filling fraction $\ensuremath{\nu}=1,$ the quantum Hall ferromagnet contains multiple Skyrmion spin excitations. This multi-Skyrmion system has a tremendously rich quantum-critical structure.
Skyrme crystal in a two-dimensional electron gas.
The filling factor dependence of the electron spin-polarization, calculated for the square lattice Skyrme crystal, is in excellent agreement with recent experiments.
Optically pumped NMR evidence for finite-size skyrmions in GaAs quantum wells near Landau level filling nu =1.
The Knight shift and spin-lattice relaxation time of the Ga nuclei located in n-doped GaAs quantum wells are measured using optically pumped NMR, showing evidence that the charged excitations of the v = 1 ground state are finite-size Skyrmions.