Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The effect of charge fluctuation on a normal-superconducting-normal
  single-electron transistor   We theoretically investigate quantum fluctuation of charge between even and
odd states of a normal-superconducting-normal single-electron tunneling
transistor. It is shown that due to the superconducting gap, the charge
fluctuation in the Coulomb blockade regime for even state is larger than that
for odd state. We show that large energy correction in the former regime caused
by charge fluctuation can be explained by considering the charging energy
renormalization.

14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph