Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: mK-STM Studies of the Temperature- and Field-dependence of the
  Quasiparticle Spectrum of Sr2RuO4   Atomic-resolution scanning tunneling spectroscopy is used to study the
spectrum of quasiparticle states in superconducting Sr2RuO4. The measured
temperature dependence of the quasiparticle spectrum is consistent with a
multi-band superconducting order parameter with one band exhibiting a line of
nodes, if a constant density of states offset can be ascribed to a surface
effect. In magnetic fields $H<H_{c2}$, a vortex lattice, square and oriented
parallel to the <110> direction of the RuO2 lattice, is detected by
spectroscopic imaging. Each vortex exhibits one flux quantum and a strong
zero-bias conductance peak.

1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph