Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Flat bands and $Z_2$ topological phases in a non-Abelian kagome lattice   We introduce a non-Abelian kagome lattice model that has both time-reversal
and inversion symmetries and study the flat band physics and topological phases
of this model. Due to the coexistence of both time-reversal and inversion
symmetries, the energy bands consist of three doubly degenerate bands whose
energy and conditions for the presence of flat bands could be obtained
analytically, allowing us to tune the flat band with respect to the other two
dispersive bands from the top to the middle and then to the bottom of the three
bands. We further study the gapped phases of the model and show that they
belong to the same phase as the band gaps only close at discrete points of the
parameter space, making any two gapped phases adiabatically connected to each
other without closing the band gap. Using the Pfaffian approach based on the
time-reversal symmetry and parity characterization from the inversion symmetry,
we calculate the bulk topological invariants and demonstrate that the unique
gapped phases belong to the $Z_2$ quantum spin Hall phase, which is further
confirmed by the edge state calculations.

23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
3
The categories of this paper are: physics
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg