Fig. 2: Demonstration of an ideal Kramers nodal line (KNL) metal, In_1/2TaS₂.

a Bulk Bloch spectral function of In_1/2TaS₂ calculated from the full-potential fully-relativistic Korringa–Kohn–Rostoker (KKR) method, highlighting the single KNL band crossing the Fermi level. b Spin projection along z for the bulk band dispersion in (a). c Fermi surface of In_1/2TaS₂ measured by angle-resolved photoemission spectroscopy (ARPES). The KNL direction \(\bar{\Gamma }-\bar{M}\) is denoted by the purple line. All experimental data in the figure were taken with 75 eV photons of p polarization as indicated at 15 K. d One-step calculation of the Fermi surface using the same experimental conditions, where the theoretical Fermi level has been shifted up by 75 meV to achieve the best match with the data. e Spin polarization along z extracted from the same one-step calculation in (d). f, g Electronic band structure along \(\bar{\Gamma }-\bar{M}-\bar{K}-\bar{\Gamma }\) showing the KNL dispersions measured in ARPES and predicted by one-step calculations. s_z pol.: s_z polarization. SOC: spin-orbit coupling.