Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Metamagnetic quantum criticality in Sr3Ru2O7 studied by thermal
  expansion   We report low-temperature thermal expansion measurements on the bilayer
ruthenate Sr$_3$Ru$_2$O$_7$ as a function of magnetic field applied
perpendicular to the Ruthenium-oxide planes. The field-dependence of the c-axis
expansion coefficient indicates the accumulation of entropy close to 8 Tesla,
related to an underlying quantum critical point. The latter is masked by two
first-order metamagnetic transitions which bound a regime of enhanced entropy.
Outside this region the singular thermal expansion behavior is compatible with
the predictions of the itinerant theory for a two-dimensional metamagnetic
quantum critical end point.

3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin