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Heavy Quasi-Particle in the Two-Orbital Hubbard Model

Yoshiki Imai·Norio Kawakami
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Abstract

The two-orbital Hubbard model with the Hund coupling is investigated in a metallic phase close to the Mott insulator. We calculate the one-particle spectral function and the optical conductivity within dynamical mean field theory, for which the effective impurity problem is solved by using the non-crossing approximation. For a metallic system close to quarter filling, a heavy quasi-particle band is formed by the Hubbard interaction, the effective mass of which is not so sensitive to the orbital splitting and the Hund coupling. In contrast, a heavy quasi-particle band near half filling disappears in the presence of the orbital splitting, but is induced again by the introduction of the Hund coupling, resulting in a different type of heavy quasi-particles.

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Yoshiki Imai, Norio Kawakami. 2001-06-11. Heavy Quasi-Particle in the Two-Orbital Hubbard Model. https://doi.org/10.1143/jpsj.70.2365

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