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DOE OSTI · 2447213

Quantum Bipolaron Superconductivity from Quadratic Electron-Phonon Coupling

Han, Zhaoyu·Kivelson, Steven A.·Volkov, Pavel A.
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Abstract

When the electron-phonon coupling is quadratic in the phonon coordinates, electrons can pair to form bipolarons due to phonon zero-point fluctuations, a purely quantum effect. Here we study superconductivity originating from this pairing mechanism in a minimal model and reveal that, in the strong coupling regime, the critical temperature (T c ) is only mildly suppressed by the coupling strength, in stark contrast to the exponential suppression in linearly coupled systems, thus implying higher optimal T c values. We demonstrate that large coupling constants of this flavor are achieved in known materials such as perovskites, and discuss strategies to realize such superconductivity using superlattices.

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75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYelectron-phonon couplingpairing mechanismssuperconductivity

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Han, Zhaoyu, Kivelson, Steven A., Volkov, Pavel A.. 2024-05-31. Quantum Bipolaron Superconductivity from Quadratic Electron-Phonon Coupling. https://doi.org/10.1103/physrevlett.132.226001

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