Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A cluster-based mean-field, perturbative and coupled-cluster theory
  description of strongly correlated systems   We introduce cluster-based mean-field, perturbation and coupled-cluster
theories to describe the ground state of strongly-correlated spin systems. In
cluster mean-field, the ground state wavefunction is written as a simple tensor
product of optimized cluster states. The cluster-language and the mean-field
nature of the ansatz allows for a straightforward improvement based on
perturbation theory and coupled-cluster, to account for inter-cluster
correlations. We present benchmark calculations on the 2D square $J_1-J_2$
Heisenberg model, using cluster mean-field, second-order perturbation theory
and coupled-cluster. We also present an extrapolation scheme that allows us to
compute thermodynamic limit energies very accurately. Our results indicate
that, even with relatively small clusters, the correlated methods can provide
an accurate description of the Heisenberg model in the regimes considered. Some
ways to improve the results presented in this work are discussed.

27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin