2023

Ning Jinliang; Lane Christopher; Zhang Yubo; Matzelle Matthew; Singh Bahadur; Barbiellini Bernardo; Markiewicz Robert S.; Bansil Arun; Sun Jianwei

The role of lattice dynamics in unconventional high-temperature superconductivity is still vigorously debated. Theoretical insights into this problem have long been prevented by the absence of an accurate first-principles description of the combined electronic, magnetic, and lattice degrees of freedom. Utilizing the recently constructed r2SCAN density functional that stabilizes the antiferromagnetic (AFM) state of the pristine oxide YBa2Cu3O6, we faithfully reproduce the experimental dispersion of key phonon modes. We further find significant magnetoelastic coupling in numerous high-energy Cu-O bond stretching optical branches, where the AFM results improve over the soft nonmagnetic phonon bands.