Pseudospin vortex-antivortex states with interwoven spin textures in double layer quantum Hall systems

Abstract

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 the quantum Hall or in the compressibles states that occur at filling factor $\nu =1.$ These experiments imply that the quasiparticles at $\nu =1$ could have both spin and pseudospin textures i.e. they could be CP${}^3$ skyrmions. Using a microscopic unrestricted Hartree-Fock approximation, we compute the energy of several crystal states with spin, pseudospin and mixed spin-pseudospin textures around $\nu =1$ as a function of interlayer separation $d$ for different values of tunneling (${\Delta }_{SAS}$), Zeeman (${\Delta }_Z$), and bias (${\Delta }_b$) energies. We show that in some range of these parameters, crystal states involving a certain amount of spin depolarization have lower energy than the fully spin polarized crystals. We study this depolarization dependence on $d,{\Delta }_{SAS},{\Delta }_Z$ and ${\Delta }_b$ and discuss how it can lead to the fast NMR relaxation rate observed experimentally.

19 pages including 10 eps figures

References in corpus (19)

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• Meron Pseudospin Solutions in Quantum Hall Systems
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Cited by in corpus (11)

• Magnetic bimerons as skyrmion analogues in in-plane magnets
• Orbital and interlayer Skyrmions crystals in bilayer graphene
• Entanglement Skyrmions in multicomponent quantum Hall systems
• Skyrme and Wigner crystals in graphene
• Pinning mode resonance of a Skyrme crystal near Landau level filling factor $\nu$=1
• Intrinsic gap and exciton condensation in the nu_T=1 bilayer system
• Collective modes of CP(3) Skyrmion crystals in quantum Hall ferromagnets
• Theory of Activated Transport in Bilayer Quantum Hall Systems
• Bilayer Quantum Hall Ferromagnet in a Periodic Potential
• Pseudospin Transfer Torques in Semiconductor Electron Bilayers
• Wigner solids of wide quantum wells near Landau filling $\nu =1$