Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Second-harmonic current-phase relation in Josephson junctions with
  ferromagnetic barriers   We report the observation of a current-phase relation dominated by the second
Josephson harmonic in superconductor-ferromagnet-superconductor junctions. The
exotic current-phase relation is realized in the vicinity of a
temperature-controlled 0-to-$\pi$ junction transition, at which the first
Josephson harmonic vanishes. Direct current-phase relation measurements, as
well as Josephson interferometry, non-vanishing supercurrent and half-integer
Shapiro steps at the 0-$\pi$ transition self-consistently point to an intrinsic
second harmonic term, making it possible to rule out common alternative origins
of half-periodic behavior. While surprising for diffusive multimode junctions,
the large second harmonic is in agreement with theory predictions for thin
ferromagnetic interlayers.

16
The categories of this paper are: stat
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org