Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamical structure factor of random antiferromagnetic Heisenberg spin
  chains   Combining quantum Monte Carlo simulations with the maximum entropy method, we
study the dynamical structure factor $S(k,\omega)$ of spin-1/2
antiferromagnetic Heisenberg chains with various random bond distributions. We
emphasize the crossover behavior in the dynamical properties from pure chain to
disorder-dominated random singlet phase due to bond randomness. For the
distribution corresponding to the infinite randomness fixed point,
$S(k,\omega)$ develops broad non-spinon excitations as well as the
random-singlet peak near $(k, \omega) = (\pi, 0)$, consistent with the known
results obtained by the real-space renormalization group method. For weak
disorder, however, we find clear signature of spinon excitations, reminiscent
of pure spin chains, blurred by disorder. We discuss the implication for
experiments on random-bond antiferromagnetic spin chains, realizable, e.g., in
BaCu$_2$(Si$_x$Ge$_{1-x}$)$_2$O$_7$.

27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio