Exotic Physics in the Negative-U, Extended-Hubbard Model for Barium Bismuthates?

Taraphder, A and Krishnamurthy, HR and Pandit, R and Ramakrishnan, TV (1993) Exotic Physics in the Negative-U, Extended-Hubbard Model for Barium Bismuthates? In: EPL: Europhysics Letters, 21 (1). pp. 79-85.

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Abstract

We point out possibilities for exotic physics in barium bismuthates, from a detailed study of the negative-U, extended-Hubbard model proposed for these systems. We emphasize the different consequences of electronic and phononic mechanisms for negative U. We show that, for an electronic mechanism, the semiconducting phases must be unique, with their transport properties dominated by charge ± 2e Cooperon bound states. This can explain the observed difference between the optical and transport gaps. We propose other experimental tests for this novel mechanism of charge transport.

Item Type:	Journal Article
Publication:	EPL: 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:	08 Feb 2011 09:19
Last Modified:	08 Feb 2011 09:19
URI:	http://eprints.iisc.ac.in/id/eprint/35467

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