Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Giant oscillations of the density of states and the conductance in a
  ferromagnetic conductor coupled to two superconductors   Giant oscillations of the density of electronic states and the differential
conductance of a superconductor-ferromagnet-superconductor structure are
predicted for the case when the exchange energy, $I_0$, due to the interaction
between the electron spin and the spontaneous moment of the ferromagnet is
smaller than the superconductor energy gap, $\Delta$. The effect is due to the
extremely large degeneration of the energy level $\epsilon = I_0$ when the
superconductor phase difference $\phi$ is close to odd multiple of $\pi$
($\epsilon$ is the electron energy measured from the Fermi-energy). This
quantum interference effect persists even in long ferromagnetic bridges whose
length much exceeds the ''magnetic length'' ($\hbar v_{F}/I_{0}$ in the
ballistic regime and $\sqrt{\hbar D/I_0}$ in the diffusive regime; $D$ is the
electron diffusion constant). The predicted effect allows a direct spectroscopy
of Andreev levels in the ferromagnet as well as a direct measurement of the
exchange energy,$I_0$.

1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci