Cavity-enhanced superconductivity in MgB₂ from first-principles quantum electrodynamics (QEDFT).

Area of Science:

• Condensed Matter Physics
• Quantum Electrodynamics
• Materials Science

Background:

• Superconductivity is a quantum mechanical phenomenon where certain materials exhibit zero electrical resistance.
• Controlling superconductivity with external fields, like strong laser pulses, can induce non-equilibrium states.
• Phonon-mediated superconductivity is a key mechanism in many conventional superconductors.

Purpose of the Study:

• To theoretically investigate the effect of cavity-generated vacuum fluctuations on equilibrium phonon-mediated superconductivity.
• To explore the potential for enhancing superconductive properties in solid-state materials using quantum electrodynamical effects.
• To determine the impact of strong light-matter coupling on the superconducting transition temperature (Tc) of MgB2.

Main Methods:

• Utilized the ab initio quantum electrodynamical density-functional theory (QED-DFT) approximation.
• Simulated MgB2 within realistic cavity setups under varying polarization conditions.
• Analyzed the modification of electronic structure and phononic dispersion due to vacuum fluctuations.

Main Results:

• Demonstrated that vacuum fluctuations in a cavity can influence equilibrium superconductive pairing.
• Observed a potential enhancement of the superconducting transition temperature (Tc) by up to 10% in MgB2.
• Showcased the nonperturbative modification of electronic and phononic properties under strong light-matter coupling.

Conclusions:

• Strong light-matter coupling, mediated by cavity vacuum fluctuations, offers a novel route to control equilibrium superconductivity.
• Cavity materials engineering presents a pathway for experimental realization of light-controlled superconductivity in solid-state systems.
• The findings suggest that manipulating quantum vacuum states can tune material properties beyond conventional methods.