Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase diagram of interacting spinless fermions on the honeycomb lattice:
  A comprehensive exact diagonalization study   We investigate the phase diagram of spinless fermions with nearest and
next-nearest neighbour density-density interactions on the honeycomb lattice at
half-filling. Using Exact Diagonalization techniques of the full Hamiltonian
and constrained subspaces, combined with a careful choice of finite-size
clusters, we determine the different charge orderings that occur for large
interactions. In this regime we find a two-sublattice N\'eel-like state, a
charge modulated state with a tripling of the unit cell, a zig-zag phase and a
novel charge ordered states with a 12 site unit cells we call N\'eel domain
wall crystal, as well as a region of phase separation for attractive
interactions. A sizeable region of the phase diagram is classically degenerate,
but it remains unclear whether an order-by-disorder mechanism will lift the
degeneracy. For intermediate repulsion we find evidence for a Kekul\'e or
plaquette bond-order wave phase. We also investigate the possibility of a
spontaneous Chern insulator phase (dubbed topological Mott insulator), as
previously put forward by several mean-field studies. Although we are unable to
detect convincing evidence for this phase based on energy spectra and order
parameters, we find an enhancement of current-current correlations with the
expected spatial structure compared to the non-interacting situation. While for
the studied $t{-}V_1{-}V_2$ model the phase transition to the putative
topological Mott insulator is preempted by the phase transitions to the various
ordered states, our findings might hint at the possibility for a topological
Mott insulator in an enlarged Hamiltonian parameter space, where the competing
phases are suppressed.

1
The categories of this paper are: cs
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
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The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio