Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-coplanar magnetism, topological density wave order and emergent
  symmetry at half-integer filling of moir\'{e} Chern bands   We study the impact of Coulomb interactions at half-integer filling of the
moir\'e Chern bands of twisted double-bilayer graphene and twisted mono-bilayer
graphene, using unbiased exact diagonalization complemented by unrestricted
Hartree-Fock calculations. For small intra-sublattice tunneling, $w_{AA}$, a
non-coplanar magnetic state is found which has the same symmetries as the
tetrahedral antiferromagnet of the triangular moir\'e lattice and can be
thought of as a skyrmion lattice commensurate with the moir\'e scale. The
antiferromagnetic order competes with a set of ferromagnetic, topological
charge density waves, which are favored for larger $w_{AA}$ and are associated
with an approximate emergent O(3) symmetry, `rotating' the different charge
density wave states into each other. Direct comparison with exact
diagonalization reveals that the ordered phases are accurately described within
the unrestricted Hartree-Fock approximation. Exhibiting a finite charge gap and
Chern number $C=\pm1$, the formation of charge density wave order which is
intimately connected to a skyrmion lattice phase is consistent with recent
experiments on these systems.

14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph