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

Article

关键词: SPONTANEOUS INTERLAYER COHERENCE;    STRONG MAGNETIC-FIELD;    OPTICALLY PUMPED NMR;    PHASE-TRANSITIONS;    MERON CRYSTALS;    SKYRMIONS;    INTEGER;    FERROMAGNETS;    EXCITATIONS;    BIMERONS;   

DOI  :  10.1103/PhysRevB.74.195320

来源: SCIE

【 摘 要 】

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 CP3 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.

【 授权许可】

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