2006/04/30 by Hiroaki Onishi, Takashi Hotta
Materials Science · Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Density matrix renormalization group #Excited state #Frustration #Geometry #Heisenberg model #Hubbard model #Magnetic and transport properties of perovskites and related materials #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Renormalization group #Spin (aerodynamics) #Zigzag #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.75.014410
published as Phys. Rev. B 75 (2007) 014410 · 8 pages, 6 figures, extended version
arxiv created 2006/07/24 · openalex publication_date 2007/01/10 · arxiv updated 2015/06/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In order to discuss the spin-gap formation in a multiorbital system, we analyze an eg-orbital Hubbard model on a geometrically frustrated zigzag chain by using a density-matrix renormalization group method. Due to the appearance of a ferro-orbital arrangement, the system is regarded as a one-orbital system, while the degree of spin frustration is controlled by the spatial anisotropy of the orbital. In the region of strong spin frustration, we observe a finite energy gap between ground and first-excited states, which should be called a spin-orbital gap. The physical meaning is clarified by an effective Heisenberg spin model including the correct effect of the orbital arrangement influenced by the spin excitation.