Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Coulomb Blockade without Tunnel Junctions   We find that tunnel junctions are not needed to provide single electron
effects in a metallic island. Eventually the tunnel junction may be replaced by
an arbitrary scatterer. It is important that even a {\it diffusive} scatterer
provides a sufficient isolation for single electron effects to persist. To
formulate this in exact terms, we derive and analyze the effective action that
describes an arbitrary scatterer. We also consider the fluctuations of the
effective charging energy.

2
The categories of this paper are: math
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs