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Polaron versus bipolaron in conducting polymers: a density matrix renormalization group study

Makoto Kuwabara·Yukihiro Shimoi·Shuji Abe
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Abstract

Competition between polaron and bipolaron inconjugated polymers with nondegenerate ground state is systematically studied in the extended Hubbard-Peierls model with the symmetry-breaking Brazovskii-Kirova term, using the density matrix renormalization group method combined with lattice optimization in the adiabatic approximation. We demonstrate that the relative stability of a bipolaron over two separated polarons sensitively depends on both on-site Hubbard $U$ and nearest-neighbor repulsion $V$. When $U$ is much larger than $V$, the bipolaron state is more stabilized compared with mean field calculations.

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Makoto Kuwabara, Yukihiro Shimoi, Shuji Abe. 1998-03-18. Polaron versus bipolaron in conducting polymers: a density matrix renormalization group study. https://doi.org/10.1143/jpsj.67.1521

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