Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: InAs nanowire with epitaxial aluminium as a single-electron transistor
  with fixed tunnel barriers   We report on fabrication of single-electron transistors using InAs nanowires
with epitaxial aluminium with fixed tunnel barriers made of aluminium oxide.
The devices exhibit a hard superconducting gap induced by the proximized
aluminium cover shell and they behave as metallic single-electron transistors.
In contrast to the typical few channel contacts in semiconducting devices, our
approach forms opaque multichannel contacts to a semiconducting wire and thus
provides a complementary way to study them. In addition, we confirm that
unwanted extra quantum dots can appear at the surface of the nanowire. Their
presence is prevented in our devices, and also by inserting a protective layer
of GaAs between the InAs and Al, the latter being suitable for standard
measurement methods.

15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph