Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of three-state nematicity in the triangular lattice
  antiferromagnet Fe$_{1/3}$ NbS$_2$   Nematic order is the breaking of rotational symmetry in the presence of
translational invariance. While originally defined in the context of liquid
crystals, the concept of nematic order has arisen in crystalline matter with
discrete rotational symmetry, most prominently in the tetragonal Fe-based
superconductors where the parent state is four-fold symmetric. In this case the
nematic director takes on only two directions, and the order parameter in such
"Ising-nematic" systems is a simple scalar. Here, using a novel
spatially-resolved optical polarimetry technique, we show that a qualitatively
distinct nematic state arises in the triangular lattice antiferromagnet
Fe$_{1/3}$NbS$_2$. The crucial difference is that the nematic order on the
triangular lattice is a Z$_3$, or three-state Potts-nematic order parameter. As
a consequence, the anisotropy axes of response functions such as the
resistivity tensor can be continuously re-oriented by external perturbations.
This discovery provides insight into realizing devices that exploit analogies
with nematic liquid crystals.

34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th