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arXiv · 2409.14132

Effects of phonon dispersion on the bond-bipolaron superconductivity

Chao Zhang·Nikolay Prokof'ev·Boris Svistunov
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Abstract

We employ the diagrammatic Monte Carlo method based on lattice path-integral representaion of the particle sector and real-space diagrammatics of the phonon sector to study effects of optical phonon dispersion on Bose-Einstein condensation of bipolarons in the bond model. For dispersionless phonons with frequency $\omega$ this model was recently shown to give rise to small-size, light-mass bipolarons that undergo a superfluid transition at high values of the $T_c/\omega$ ratio. We find that for dispersive phonons, $T_c$ remains relatively high over a broader range of the coupling strength and even keeps increasing in the deep adiabatic regime both in two and three dimensions. This result implies that phonon dispersion is not a limiting factor in the search for new materials with high superconducting temperatures.

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Chao Zhang, Nikolay Prokof'ev, Boris Svistunov. 2024-09-21. Effects of phonon dispersion on the bond-bipolaron superconductivity. https://arxiv.org/abs/2409.14132

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