Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Valence-Bond-Glass State with Singlet Gap in the Spin-1/2 Square-Lattice
  Random $J_1$-$J_2$ Heisenberg Antiferromagnet Sr$_2$CuTe$_{1-x}$W$_x$O$_6$   The double-perovskite compounds Sr$_2$CuTeO$_6$ and Sr$_2$CuWO$_6$ are
magnetically described as quasi-two-dimensional spin-1/2 square-lattice
$J_1{-}J_2$ Heisenberg antiferromagnets with predominant $J_1$ and $J_2$
exchange interactions, respectively. We report the low-temperature magnetic
properties of Sr$_2$CuTe$_{1-x}$W$_x$O$_6$ with randomness in the magnitudes of
$J_1$ and $J_2$. It was found that the low-temperature specific heat for
$0.1\leq x \leq 0.5$ has a large component proportional to the temperature $T$
above 1.2 K, although the low-temperature specific heat for the two parent
systems is approximately proportional to $T^3$. With decreasing temperature
below 1.2 K, the $T$-linear component decreases rapidly toward zero, which is
insensitive to the magnetic field up to 9 T. This is suggestive of the singlet
excitation decoupled from the magnetic field. The NMR spectrum for $x=0.2$
exhibits no long-range order down to 1.8 K. These results indicates that the
ground state of Sr$_2$CuTe$_{1-x}$W$_x$O$_6$ is a valence-bond-glass state with
singlet gaps.

26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn