Observation of Topological Nodal Fermion Semimetal Phase in ZrSiS

TL;DR

This study uses ARPES to identify ZrSiS as a topological nodal fermion semimetal, revealing multiple Fermi surface pockets and supporting its potential for exploring exotic quantum states and engineering 2D topological insulators.

Contribution

First experimental confirmation of the spinless nodal fermion semimetal phase in ZrSiS supported by first-principles calculations.

Findings

Multiple Fermi surface pockets identified in ZrSiS

Experimental evidence of the topological nodal fermion semimetal phase

ZrSiS family as a platform for exotic quantum states

Abstract

Unveiling new topological phases of matter is one of the current objectives in condensed matter physics. Recent experimental discoveries of Dirac and Weyl semimetals prompt to search for other exotic phases of matter. Here we present a systematic angle-resolved photoemission spectroscopy (ARPES) study of ZrSiS, a prime topological nodal semimetal candidate. Our wider Brillouin zone (BZ) mapping shows multiple Fermi surface pockets such as the diamond-shaped Fermi surface, ellipsoidal-shaped Fermi surface, and a small electron pocket encircling at the zone center (G) point, the M point and the X point of the BZ, respectively. We experimentally establish the spinless nodal fermion semimetal phase in ZrSiS, which is supported by our first-principles calculations. Our findings evidence that the ZrSiS-type of material family is a new platform to explore exotic states of quantum matter, while these materials are expected to provide an avenue for engineering two-dimensional topological insulator systems.