Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universality and stability of the edge states of chiral-symmetric
  topological semimetals and surface states of the Luttinger semimetal   We theoretically demonstrate that the chiral structure of the nodes of nodal
semimetals is responsible for the existence and universal local properties of
the edge states in the vicinity of the nodes. We perform a general analysis of
the edge states for an isolated node of a 2D semimetal, protected by {\em
chiral symmetry} and characterized by the topological winding number $N$. We
derive the asymptotic chiral-symmetric boundary conditions and find that there
are $N+1$ universal classes of them. The class determines the numbers of
flat-band edge states on either side off the node in the 1D spectrum and the
winding number $N$ gives the {\em total} number of edge states. We then show
that the edge states of chiral nodal semimetals are {\em robust}: they persist
in a finite-size {\em stability region} of parameters of chiral-asymmetric
terms. This significantly extends the notion of 2D and 3D topological nodal
semimetals. We demonstrate that the Luttinger model with a quadratic node for
$j=\frac32$ electrons is a 3D topological semimetal in this new sense and
predict that $\alpha$-Sn, HgTe, possibly Pr$_2$Ir$_2$O$_7$, and many other
semimetals described by it are topological and exhibit surface states.

34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int