Hamiltonian description of composite fermions: Magnetoexciton dispersions

Article

关键词: QUANTUM HALL STATES;    DIMENSIONAL ELECTRON-GAS;    STRONG MAGNETIC-FIELD;    FILLED LANDAU-LEVEL;    OPTICALLY PUMPED NMR;    CHERN-SIMONS THEORY;    COLLECTIVE EXCITATIONS;    FRACTIONAL-STATISTICS;    RESPONSE FUNCTIONS;    SPIN POLARIZATION;   

DOI  :  10.1103/PhysRevB.60.13702

来源: SCIE

【 摘 要 】

A microscopic Hamiltonian theory of the FQHE, developed by Shankar and myself based on the fermionic Chern-Simons approach, has recently been quite successful in calculating gaps in fractional quantum hall states, and in predicting approximate scaling relations between the gaps of different fractions. I now apply this formalism towards computing magnetoexciton dispersions (including spin-hip dispersions) in the v = 1/3, 2/5, and 3/7 grapped fractions, and find approximate agreement with numerical results. I also analyze the evolution of these dispersions with increasing sample thickness, modelled by a potential soft at high momenta. New results are obtained for instabilities as a function of thickness for 2/5 and 3/7, and it is shown that the spin-polarized 2/5 state, in contrast to the spin-polarized 1/3 state, cannot be described as a simple quantum ferromagnet.

【 授权许可】

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