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A New Theory of Doped Manganites Exhibiting Colossal Magnetoresistance

Krishnamurthy, HR (2005) A New Theory of Doped Manganites Exhibiting Colossal Magnetoresistance. In: Pramana Journal of Physics, 64 (6). pp. 1063-1074.

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Abstract

Rare earth manganites doped with alkaline earths, namely $Re_1_-_xAxMnO_3$, exhibit colossal magnetoresistance, metal insulator transitions, competing magnetic, orbital and charge ordering, and many other interesting but poorly understood phenomena. In this article I outline our recent theory based on the idea that in the presence of strong Jahn-Teller, Coulomb and Hund's couplings present in these materials, the low-energy electronic states dynamically reorganize themselves into two sets: one set (l) which are polaronic, i.e., localized and accompanied by large local lattice distortion, and another (b) which are non-polaronic and band-like. The coexistence of the radically different l and b states, and the sensitive dependence of their relative energies and occupation upon doping x, temperature T, magnetic field H, etc., underlies the unique effects seen in manganites. I present results from strong correlation calculations using dynamical mean-field theory and simulations on a new 2-fluid model which accord with a variety of observations.

Item Type: Journal Article
Additional Information: The copyright for this article belongs to Indian Academy of Sciences
Keywords: Colossal magnetoresistance;manganites;Jahn-Teller polarons; strong correlation
Department/Centre: Division of Physical & Mathematical Sciences > Physics
Date Deposited: 22 Aug 2005
Last Modified: 19 Sep 2010 04:19
URI: http://eprints.iisc.ernet.in/id/eprint/3405

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