Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radio-Frequency Single-Electron Refrigerator   We propose a cyclic refrigeration principle based on mesoscopic electron
transport. Synchronous sequential tunnelling of electrons in a
Coulomb-blockaded device, a normal metal-superconductor single-electron box,
results in a cooling power of $\sim k_{\rm B}T \times f$ at temperature $T$
over a wide range of cycle frequencies $f$. Electrostatic work, done by the
gate voltage source, removes heat from the Coulomb island with an efficiency of
$\sim k_{\rm B}T/\Delta$, where $\Delta$ is the superconducting gap. The
performance is not affected significantly by non-idealities, for instance by
offset charges. We propose ways of characterizing the system and of its
practical implementation.

10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom