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arXiv · 1904.07324

Magnetic response of Sr$_2$RuO$_4$: quasi-local spin fluctuations due to Hund's coupling

Hugo U. R. Strand·Manuel Zingl·Nils Wentzell·Olivier Parcollet·Antoine Georges
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Abstract

We study the magnetic susceptibility in the normal state of Sr$_2$RuO$_4$ using dynamical mean-field theory including dynamical vertex corrections. Besides the well known incommensurate response, our calculations yield quasi-local spin fluctuations which are broad in momentum and centered around the $Γ$ point, in agreement with recent inelastic neutron scattering experiments [P. Steffens, et al., Phys. Rev. Lett. 122, 047004 (2019)]. We show that these quasi-local fluctuations are controlled by the Hund's coupling and account for the dominant contribution to the momentum-integrated response. While all orbitals contribute equally to the incommensurate response, the enhanced $Γ$ point response originates from the planar xy orbital.

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Hugo U. R. Strand, Manuel Zingl, Nils Wentzell, Olivier Parcollet, Antoine Georges. 2019-04-15. Magnetic response of Sr$_2$RuO$_4$: quasi-local spin fluctuations due to Hund's coupling. https://doi.org/10.1103/physrevb.100.125120

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