Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exact Analysis of Entanglement in Gapped Quantum Spin Chains   We investigate the entanglement properties of the valence-bond-solid states
with generic integer-spin $S$. Using the Schwinger boson representation of the
valence-bond-solid states, the entanglement entropy, the von Neumann entropy of
a subsystem, is obtained exactly and its relationship with the usual
correlation function is clarified. The saturation value of the entanglement
entropy, $2 \log_2 (S+1)$, is derived explicitly and is interpreted in terms of
the edge-state picture. The validity of our analytical results and the
edge-state picture is numerically confirmed. We also propose a novel
application of the edge state as a qubit for quantum computation.

5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int