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

Sanjeev Kumar·Arno P. Kampf·Pinaki Majumdar
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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.

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Sanjeev Kumar, Arno P. Kampf, Pinaki Majumdar. 2006-09-28. The Effect of Disorder in an Orbitally Ordered Jahn-Teller Insulator. https://doi.org/10.1103/physrevb.75.014209

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