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arXiv · 2404.08122

Cavity engineered phonon-mediated superconductivity in MgB$_2$ from first principles quantum electrodynamics

I-Te Lu·Dongbin Shin·Mark Kamper Svendsen·Hannes Hübener·Umberto De Giovannini·Simone Latini·Michael Ruggenthaler·Angel Rubio
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Abstract

Strong laser pulses can control superconductivity, inducing non-equilibrium transient pairing by leveraging strong-light matter interaction. Here we demonstrate theoretically that equilibrium ground-state phonon-mediated superconductive pairing can be affected through the vacuum fluctuating electromagnetic field in a cavity. Using the recently developed ab initio quantum electrodynamical density-functional theory approximation, we specifically investigate the phonon-mediated superconductive behavior of MgB$_2$ under different cavity setups and find that in the strong light-matter coupling regime its superconducting transition temperature can be, in principles, enhanced by $\approx 73\%$ ($\approx 40\%$) in an in-plane (out-of-plane) polarized cavity. However, in a realistic cavity, we expect the T$_{\rm{c}}$ of MgB$_2$ can increase, at most, by $5$ K via photon vacuum fluctuations. The results highlight that strong light-matter coupling in extended systems can profoundly alter material properties in a non-perturbative way by modifying their electronic structure and phononic dispersion at the same time. Our findings indicate a pathway to the experimental realization of light-controlled superconductivity in solid-state materials at equilibrium via cavity-material engineering.

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I-Te Lu, Dongbin Shin, Mark Kamper Svendsen, Hannes Hübener, Umberto De Giovannini, Simone Latini, Michael Ruggenthaler, Angel Rubio. 2024-06-20. Cavity engineered phonon-mediated superconductivity in MgB$_2$ from first principles quantum electrodynamics. https://doi.org/10.1073/pnas.2415061121

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