Large Enhancement of Ferro-Magnetism under Collective Strong Coupling of YBCO Nanoparticles

TL;DR

This study demonstrates a 700-fold enhancement of ferromagnetism in YBCO nanoparticles through collective strong coupling, indicating a new approach to develop advanced magnetic and spintronic nanodevices at room temperature.

Contribution

It reports the first significant enhancement of ferromagnetism in oxide nanoparticles via collective strong coupling at room temperature.

Findings

700-fold increase in ferromagnetism of YBCO nanoparticles

Magnetic moment reaches 0.90 μ_B/mol at room temperature

Strong coupling competes with superconductivity at low temperature

Abstract

Light-matter strong coupling in the vacuum limit has been shown to enhance material properties over the past decade. 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 cooperative strong coupling at room temperature. The magnetic moment reaches 0.90 $\mu_{\rm B}$/mol, and with such a high value, it competes with YBa$_2$Cu$_3$O$_{7-x}$ superconductivity at low temperature. This strong ferromagnetism at room temperature suggest that strong coupling is a new tool for the development of next generations of magnetic and spintronic nanodevices.