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arXiv · cond-mat/0611355

Polaron cross-overs and d-wave superconductivity in Hubbard-Holstein model

R. Ramakumar·A. N. Das
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Abstract

We present a theoretical study of superconductivity of polarons in the Hubbard-Holstein model. A residual kinematic interaction proportional to the square of the polaron hopping energy between polarons and phonons provides a pairing field for the polarons. We find that superconducting instability in the d-wave channel is possible with small transition temperatures which is maximum in the large to small polaron cross-over region. An s-wave instability is found to be not possible when the effective on-site interaction between polarons is repulsive.

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R. Ramakumar, A. N. Das. 2006-11-14. Polaron cross-overs and d-wave superconductivity in Hubbard-Holstein model. https://doi.org/10.1140/epjb%2Fe2004-00309-4

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