Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Characterization of localized effective spins in gapped quantum spin
  chains   We study properties of localized effective spins induced in gapped quantum
spin chains by local inhomogeneities of the lattice. As a prototype, we study
effective spins induced in impunity sites doped AKLT model by constructing the
exact ground state in a matrix product state (MPS) form. We characterize their
responses to external fields by studying an extended Zeeman interaction. We
also study the antiferromagnetic bond-alternating Heisenberg chain with defect
structures. For this model, an MPS representation similar to that for the AKLT
model, "a uniform MPS with windows", is constructed, and it gives a good
approximation of the ground state. We discuss the trade-off relation between
the window length and the precision of the MPS ansatz. The effective exchange
interaction between the induced spins is also investigated by using this
representation.

27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org