Zero-temperature insulator-metal transition in doped manganites

Pai, Venketeswara G and Hassan, SR and Krishnamurthy, HR and Ramakrishnan, TV (2003) Zero-temperature insulator-metal transition in doped manganites. In: Europhysics Letters, 64 (5). pp. 696-702.

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Abstract

We study the transition at T = 0 from a ferromagnetic insulating to a ferromagnetic metallic phase in manganites as a function of hole doping using an effective low-energy model Hamiltonian proposed by us recently. The model incorporates the quantum nature of the dynamic Jahn-Teller (JT) phonons strongly coupled to orbitally degenerate electrons as well as strong Coulomb correlation effects, and leads naturally to the coexistence of localized (JT polaronic) and band-like electronic states. We study the insulator-metal transition as a function of doping as well as of the correlation strength U and JT gain in energy $E_{JT}$, and find, for realistic values of parameters, a ground-state phase diagram in agreement with experiments. We also discuss how several other features of manganites as well as differences in behaviour among manganites can be understood in terms of our model.

Item Type:	Journal Article
Publication:	Europhysics Letters
Publisher:	EDP Sciences
Additional Information:	Copyright of this article belongs to EDP Sciences.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	27 Nov 2007
Last Modified:	19 Sep 2010 04:25
URI:	http://eprints.iisc.ac.in/id/eprint/6193

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