Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnon-bound-state hierarchy for the two-dimensional transverse-field
  Ising model in the ordered phase   In the ordered phase for an Ising ferromagnet, the magnons are attractive to
form a series of bound states with the mass gaps, $m_2<m_3 < \dots$. Each ratio
$m_{2,3,\dots}/m_1$ ($m_1$: the single-magnon mass) is expected to be a
universal constant in the vicinity of the critical point. In this paper, we
devote ourselves to the $(2+1)$-dimensional counterpart, for which the
universal hierarchical character remains unclear. We employed the exact
diagonalization method, which enables us to calculate the dynamical
susceptibility via the continued-fraction expansion. Thereby, we observe a
variety of signals including $m_{2,3,4}$, and the spectrum is analyzed with the
finite-size-scaling method to estimate the universal mass-gap ratios.

20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph