Large Enhancement of Ferromagnetism under a Collective Strong Coupling of YBCO Nanoparticles
Anoop Thomas, Éloïse Devaux, Kalaivanan Nagarajan, Guillaume Rogez, Marcus Seidel, Fanny Richard, Cyriaque Genet, Marc Drillon, Thomas W. Ebbesen
Abstract
High Resolution Image Download MS PowerPoint Slide Light–Matter strong coupling in the vacuum limit has been shown, over the past decade, to enhance material properties. Oxide nanoparticles are known to exhibit weak ferromagnetism due to vacancies in the lattice. Here we report the 700-fold enhancement of the ferromagnetism of YBa 2 Cu 3 O 7– x nanoparticles under a cooperative strong coupling at room temperature. The magnetic moment reaches 0.90 μ B /mol, and with such a high value, it competes with YBa 2 Cu 3 O 7– x superconductivity at low temperatures. This strong ferromagnetism at room temperature suggest that strong coupling is a new tool for the development of next-generation magnetic and spintronic nanodevices.