Observation of gapless nodal-line states in NdSbTe

Lanthanide ($Ln$)-based systems in $\mathrm{ZrSiS}$-type nodal-line semimetals have been subjects of research investigations as grounds for studying the interplay topology with possible magnetic ordering and electronic correlations that may originate from presence $Ln\phantom{\rule{0.28em}{0ex}}4f$ electrons. In this study, we carried out a thorough study $Ln\mathrm{SbTe}$ system, $\mathrm{NdSbTe}$, by using angle-resolved photoemission spectroscopy along first-principles calculations thermodynamic measurements. We experimentally detect multiple gapless states, which is well supported calculations. A dispersive an almost nondispersive nodal line exist bulk $X\text{\ensuremath{-}}R$ direction. Another present below Fermi level across $\mathrm{\ensuremath{\Gamma}}\text{\ensuremath{-}}M$ direction, formed bands high velocity seem to be sensitive light polarization. Our provides insight into structure alternative material system will aid towards understanding connection $Ln$ elements topological structures these systems.