Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variational Monte Carlo study of gapless spin liquid in the spin-$1/2$
  XXZ antiferromagnetic model on the kagome lattice   By using the variational Monte Carlo technique, we study the spin-$1/2$ XXZ
antiferromagnetic model (with easy-plane anisotropy) on the kagome lattice. A
class of Gutzwiller projected fermionic states with a spin Jastrow factor is
considered to describe either spin liquids (with $U(1)$ or $Z_2$ symmetry) or
magnetically ordered phases (with ${\bf q}=(0,0)$ or ${\bf q}=(4\pi/3,0)$). We
find that the magnetic states are not stable in the thermodynamic limit.
Moreover, there is no energy gain to break the gauge symmetry from $U(1)$ to
$Z_2$ within the spin-liquid states, as previously found in the Heisenberg
model. The best variational wave function is therefore the $U(1)$ Dirac state,
supplemented by the spin Jastrow factor. Furthermore, a vanishing $S=2$ spin
gap is obtained at the variational level, in the whole regime from the $XY$ to
the Heisenberg model.

10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg