Fig. 3: Loop current patterns and Brillouin zone.
From: Superconductivity in kagome metals due to soft loop-current fluctuations

The 5 LC pattern possibilities that we study a–e and a sketch of the Brillouin zone (f). Each pattern comes in a set of 3, with ordering wave vectors Mℓ = 1, 2, 3. Only the representative with the ordering wave vector M3 is shown. The other two may be obtained via C6z rotations. The red, blue, and teal sites are V, and they form a kagome lattice. The orange sites are the planar Sb, and they form a triangular lattice and live in the centers of the hexagons formed by the kagome lattice. This reflects the same color scheme as in Fig. 1. The greyed-out region is the extended 2 × 2 unit cell that our LC patterns live in. The red and blue shadings denote whether the flux of a given plaquette is out-of-page or in-page, respectively. a–c LC patterns belong to the (even-parity) \(m{M}_{2}^{+}\) irrep, while d–e belong to the (odd-parity) \(m{M}_{3}^{-}\) irrep; see Supplementary, Section 1. a, b, d have only V-V currents, while c, e have in addition V-Sb currents. Note that the ordering wave vectors Qℓ, which connect different M-points, are themselves M-points (e.g., Q3 = M2 − M1 = M3 = − M3 up to a reciprocal lattice vector). The color scheme for these three M-vectors (red, blue, teal) is chosen to coincide with the sublattice weight of the kagome sites (also red, blue, teal) at different M-points in the Brillouin zone.