The Effect of Disorder in an Orbitally Ordered Jahn-Teller Insulator

Abstract

We study a two dimensional, two-band double-exchange model for $e_g$ 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 stripe-like structures enclosing orbitally ordered domains.

10 pages, 9 figures

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Cited by in corpus (2)

• Study of Short-distance Spin and Charge Correlations and Local Density-of-States in the CMR regime of the One-Orbital Model for Manganites
• Non-magnetic B-site Impurities Induce Ferromagnetic Tendencies in CE Manganites