2003/02/27 by Satoshi Fujimoto
Chemistry · Physics and Astronomy · #Advanced Condensed Matter Physics #Band gap #Charge (physics) #Chemistry #Condensed matter physics #Electron #Inorganic Fluorides and Related Compounds #Insulator (electricity) #Materials science #Metal #Metal–insulator transition #Mott insulator #Optoelectronics #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin (aerodynamics) #Transition metal #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.67.235102
12 pages, 10 figures
arxiv created 2003/02/27 · openalex publication_date 2003/06/10 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate a (semi-)metal to insulator transition (MIT) realized in geometrically frustrated electron systems on the basis of the Hubbard model on a three-dimensional pyrochlore lattice and a two-dimensional checkerboard lattice. Using the renormalization-group method and mean-field analysis, we show that in the half-filling case, MIT occurs as a result of the interplay between geometrical frustration and electron correlation. In the insulating phase, which has a spin gap, the spin rotational symmetry is not broken, while charge ordering exists. The charge ordered state is stabilized so as to relax the geometrical frustration in the spin degrees of freedom. We also discuss the distortion of the lattice structure caused by the charge ordering. The results are successfully applied to the description of the MIT observed in the pyrochlore system Tl2Ru2O7.