2002/12/24 by Takashi Hotta · 20 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Ferromagnetism #Magnetic and transport properties of perovskites and related materials #Manganite #Materials science #Metal #Metallurgy #Phase (matter) #Physics #Quantum mechanics #Rare-earth and actinide compounds #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.67.104428
published in Physical review. B, Condensed matter 67(10) (American Physical Society) · 4 pages, Revtex, with 3 figures embedded in the text
arxiv created 2002/12/24 · openalex publication_date 2003/03/28 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The existence of a metal-insulator transition in the ferromagnetic state of models for undoped manganites is discussed here, using numerical techniques applied to the eg-orbital degenerate Hubbard model tightly coupled with Jahn-Teller distortions. The ground-state phase diagram is presented in the plane defined by the electron-phonon coupling \ensuremathλ and Coulomb interaction u. In contrast to the standard one-band Hubbard model for cuprates, the metallic phase is found to exist for finite values of both \ensuremathλ and u in the present eg-orbital Hubbard model even at half-filling, due to the Fermi-surface topology which is incompatible with the staggered orbital ordering concomitant to the insulating phase. Based on the present results, a possible scenario for the colossal magnetoresistive effect is discussed in undoped manganites.