Dirac Nodal Line and Rashba Splitting Surface States in Nonsymmorphic ZrGeTe

TL;DR

This study reveals the presence of Dirac nodal lines and Rashba-split surface states in ZrGeTe, a nonsymmorphic topological semimetal, through combined theoretical calculations and experimental techniques, highlighting its unique quantum properties.

Contribution

It provides the first comprehensive analysis of ZrGeTe's electronic structure, demonstrating floating gapless surface states with Rashba splitting and novel quasiparticle scattering features.

Findings

Floating gapless surface states at 7X7 confirmed by ARPES

Observation of Rashba splitting with helical spin texture

Identification of unique quasiparticle scattering vectors

Abstract

Dirac semimetals (DSMs) are three dimensional analogue to graphene with symmety enforced bulk Dirac nodes. Among various DSMs, ZrSiS has been attracting more interests recently, due to its three dimensional Dirac nodal line protected by the nonsymmorphic symmetry. It actually belongs to a large family of isostructural compounds with unique quantum phenomenon. Here we present a comprehensive study of the first principle calculation, angle-resolved photoemission spectroscopy (ARPES) measurements, and scanning tunneling microscope (STM) experiments on ZrGeTe, a member of the ZrSiS family with stronger spin-orbit coupling (SOC). Our band structure calculation shows the existence of floating gapless surface states at $\bar{X}$ with Rashba splitted helical spin texture, which are confirmed by our ARPES measurements. We also perform quasiparticle scattering interference (QPI) imaging and find several q-vectors, with two Umklapp scattering vectors not observed in other family compounds. All the q-vectors can be identified with joint density of states (JDOS) simulation. Our results demonstrate the interesting electronic structure of ZrGeTe and might benefit the potential application by utilizing its exotic quantum states in the future.