Observation of gapless nodal-line states in NdSbTe

TL;DR

This study identifies multiple gapless nodal-line states in NdSbTe, a lanthanide-based nodal-line semimetal, combining experimental ARPES data with first-principles calculations to deepen understanding of topological electronic structures involving Ln elements.

Contribution

It provides the first detailed experimental and theoretical investigation of nodal-line states in NdSbTe, revealing complex electronic structures influenced by lanthanide elements.

Findings

Multiple gapless nodal-line states detected experimentally.

Existence of dispersive and non-dispersive nodal-lines along specific directions.

Electronic structure insights into LnSbTe materials for topological studies.

Abstract

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