  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.
