Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Imaging the paramagnetic nonlinear Meissner effect in nodal gap
  superconductor   Boundary surfaces of nodal gap superconductors can host Andreev bound states
(ABS) which develop a paramagnetic response under external RF field in contrast
to the bulk diamagnetic response of the bulk superconductor. At low temperature
this surface paramagnetic response dominates and enhances the nonlinear RF
response of the sample. With a recently developed photoresponse imaging
technique, the anisotropy of this "paramagnetic" nonlinear Meissner response,
and its current direction (angular) and RF power dependence has been
systematically studied. A theoretical model describing the current flow in the
surface paramagnetic Andreev bound state, the bulk diamagnetic Meissner state,
and their response to optical illumination is proposed and it shows good
agreement with the experimental results.

33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con