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Correlated Electrons and Mass Enhancement on the Beta-Mn Type Lattice

Electronic structure and electron correlations of the Hubbard model on the Beta-Mn lattice have been investigated on the basis of the momentum dependent local ansatz wavefunction method. It is found that the electrons on the Beta-Mn lattice are significantly correlated as compared with those on the face centered cubic (fcc) and the body centered cubic (bcc) lattices; the correlation energy gain of the Beta-Mn lattice structure is the largest among the Beta-Mn, the fcc, and the bcc structures, and the charge fluctuations show a significant suppression. In particular, it is found that the mass enhancement factor on the Beta-Mn lattice shows a large peak around the electron number per atom n=1.1 when n is varied at the typical Coulomb interaction energy strength of transition metals. It is pointed that the large mass enhancement may explain anomalous electronic specific heat coefficient in Beta-Mn.