Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tuning entanglement and ergodicity in two-dimensional spin systems using
  impurities and anisotropy   We consider the entanglement in a two dimensional XY model in an external
magnetic field h. The model consists of a set of 7 localized spin-1/2 particles
in a two dimensional triangular lattice coupled through nearest neighbor
exchange interaction J. We examine the effect of single and double impurities
in the system as well as the degree of anisotropy on the nearest neighbor
entanglement and ergodicity of the system. We have found that the entanglement
of the system at the different degrees of anisotropy mimics that of the one
dimensional spin systems at the extremely small and large values of the
parameter h/J. The entanglement of the Ising and partially anisotropic system
show phase transition in the vicinity of h/J = 2 while the entanglement of the
isotropic system suddenly vanishes there. Also we investigate the dynamic
response of the system containing single and double impurities to an external
exponential magnetic field at different degrees of anisotropy. We have
demonstrated that the ergodicity of the system can be controlled by varying the
strength and location of the impurities as well as the degree of anisotropy of
the coupling.

19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an