Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence for a Second Order Phase Transition in Glasses at Very Low
  Temperatures -- A Macroscopic Quantum State of Tunneling Systems   Dielectric measurements at very low temperature indicate that in a glass with
the eutectic composition BaO-Al$_2$O$_3$-SiO$_2$ a phase transition occurs at
5.84 mK. Below that temperature small magnetic fields of the order of 10 $\mu$T
cause noticeable changes of the dielectric constant although the glass is
insensitive to fields up to 20 T above 10 mK. The experimental findings may be
interpreted as the signature of the formation of a new phase in which many
tunneling systems perform a coherent motion resulting in a macroscopic wave
function.

9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat