2006/09/28 by Sanjeev Kumar, A. P. Kampf, Arno P. Kampf +1
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.75.014209
published as Phys. Rev. B {\bf 75}, 014209 (2007) · 10 pages, 9 figures
arxiv created 2006/09/28 · openalex publication_date 2007/01/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study a two-dimensional, two-band double-exchange model for eg electrons coupled to Jahn-Teller distortions in the presence of quenched disorder using a recently developed Monte Carlo technique. In the absence of disorder the half-filled system at low temperatures is an orbitally ordered ferromagnetic insulator with a staggered pattern of Jahn-Teller distortions. We examine the finite-temperature transition to the orbitally disordered phase and uncover a qualitative difference between the intermediate and strongly coupled systems, including a thermally driven insulator to metal crossover in the former case. Long-range orbital order is suppressed in the presence of disorder and the system displays a tendency towards metastable states consisting of orbitally disordered stripelike structures enclosing orbitally ordered domains.