Fig. 5: Magnetism due to orbital loop currents in SRO214.
From: Unveiling unconventional magnetism at the surface of Sr2RuO4
a Illustration of the RuO4 plaquette and of the corresponding d-orbitals for the Ru atoms (red box) and p-orbitals for the O atoms (light blue box) with asymmetric loop current distributions generating magnetic flux pointing inward (yellow triangle with ‘−’ symbol) or outward (grey triangle with ‘+’ symbol) the RuO4 plane. b Possible orbital loop currents for a given RuO4 plaquette associated with the Ru–O hybridization of the dxy orbitals (top) and of the (dxz, dyz) orbitals (bottom). c Loop current states with equal (LC+ state) and opposite sign (LC− state) of the magnetic flux associated with the xy- and z-orbital sectors of the RuO plaquettes in the SRO214 supercell. d, Free energy E(ϕ)−E(0) of the LC+ (dashed lines) and LC− states (solid lines) calculated at T = 50 K for different values of the d–p Coulomb interaction \(U\) (\(U\) values given in eV units are specified in the figure legend) as a function of the order parameter ϕ which sets the amplitude of the bond current.
