Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconducting microresonators for electron spin resonance, the good,
  the bad, and the future   The field of electron spin resonance is in constant need to improve its
capabilities. Among other things, this means having better resonators which
would provide improved spin sensitivity, as well as enable larger microwave
magnetic field power conversion factors. Surface micro resonators, made of
small metallic patches on a dielectric substrate, provide very good absolute
spin sensitivity and high conversion factors due to their very small mode
volume. However, such resonators suffer from having a relatively low quality
factor, which offsets some of their significant potential advantages. The use
of superconducting patches to replace the metallic layer seems like a
reasonable and straightforward solution to the quality factor issue, at least
for measurements carried out at cryogenic temperatures. Nevertheless,
superconducting materials are not easily incorporated into setups requiring
high magnetic fields, due to electric current vortices generated in the
latter's surface. This makes the transition from normal conducing materials to
superconductors highly nontrivial. Here we present the design, fabrication, and
testing results of surface micro resonators made of yttrium barium copper oxide
(YBCO) superconducting material. We show that with a unique experimental setup,
these resonators can be made to operate well even at high fields of about 1.2
T. Furthermore, we analyze the effect of current vortices on the ESR signal and
the spins' coherence times. Finally, we provide a head to head comparison of
YBCO vs copper resonators of the same dimensions, which clearly shows their
pros and cons and directs us to future potential developments and improvements
in this field.

30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph