Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dimer XXZ Spin Ladders: Phase diagram and a Non-Trivial
  Antiferromagnetic Phase   We study the dimer $XXZ$ spin model on two-leg ladders with isotropic
Heisenberg interactions on the rung and anisotropic $XXZ$ interactions along
the rail in an external field. Combining both analytical and numerical methods,
we set up the ground state phase diagram and investigate the quantum phase
transitions and the properties of rich phases, including the full polarized,
singlet dimer, Luttinger liquid, triplon solid, and a non-trivial
antiferromagnetic phases with gap. The analytical analyses based on solvable
effective Hamiltonians are presented for clear view of the phases and
transitions. Quantum Monte Carlo and exact diagonalization methods are employed
on finite system to verify the exact nature of the phases and transitions. Of
all the phases, we pay a special attention to the gapped antiferromagnetic
phase, which is disclosed to be a non-trivial one that exhibits the
time-reversal symmetry. We also discuss how our findings could be detected in
experiment in the light of ultracold atoms technology advances.

18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat