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Excitation spectrum and effective mass of the even-fraction quantum Hall liquid

Masaru Onoda·Takahiro Mizusaki·Takaharu Otsuka·Hideo Aoki
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Abstract

To probe the nature of the even-fraction quantum Hall system, we have investigated the low-lying excitation spectrum by means of exact diagonalization for finite systems. We have found (i) a striking one-to-one correspondence (i.e., a shell structure) between the spectrum and those for free (composite) fermions, (ii) a surprisingly straight scaling plot for the excitation energy that gives a zero gap (metal) in the thermodynamic limit, (iii) the effective mass evaluated from the scaling becoming heavier for filling factor = 1/2, 1/4, 1/6, but (iv) some deviations from the single-mode or the Hartree-Fock composite fermion approximation as well.

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Masaru Onoda, Takahiro Mizusaki, Takaharu Otsuka, Hideo Aoki. 1999-12-08. Excitation spectrum and effective mass of the even-fraction quantum Hall liquid. https://doi.org/10.1103/physrevlett.84.3942

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