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

• Main Authors: Lu, I-Te, Shin, Dongbin, Svendsen, Mark Kamper, Hübener, Hannes, De Giovannini, Umberto, Latini, Simone, Ruggenthaler, Michael, Rubio, Angel
• Format: Journal Article
• Language: English
• Published: 11.04.2024
• Subjects: Physics - Applied Physics; Physics - Computational Physics; Physics - Materials Science; Physics - Superconductivity
• DOI: 10.48550/arxiv.2404.08122

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.