Fig. 3: YSR states at magnetic impurities.

Spin-density isosurface of 2H-NbSe₂ (a) and of 2H-NbSe_1.8S_0.2 (b) obtained from DFT + U calculations. Red stands for spin up and blue for spin-down charge density. The isosurface is plotted for an imbalance by 0.002 of the spin density. The Fe atom (not shown) is located on the red spot, substituting a Nb atom. Se atoms are orange and Nb atoms ochre colors. We represent the two uppermost layers (Se and Nb) from the top. In b there are S atoms in layers below, shown in the Supplementary Fig. 4. Calculations are made on four layers, using 4 × 4 × 2 sized slabs (see Supplementary Note 3, for further details). c, d Measured tunneling conductance maps at a Fe impurity in 2H-NbSe₂ (c) and in 2H-NbSe_1.8S_0.2 (d). White arrows provide the crystalline directions of the atomic Se lattice.