Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase-slip flux qubits   In thin superconducting wires, phase-slip by thermal activation near the
critical temperature is a well-known effect. It has recently become clear that
phase-slip by quantum tunnelling through the energy barrier can also have a
significant rate at low temperatures. In this paper it is suggested that
quantum phase-slip can be used to realize a superconducting quantum bit without
Josephson junctions. A loop containing a nanofabricated very thin wire is
biased with an externally applied magnetic flux of half a flux quantum,
resulting in two states with opposite circulating current and equal energy.
Quantum phase-slip should provide coherent coupling between these two
macroscopic states. Numbers are given for a wire of amorphous niobium-silicon
that can be fabricated with advanced electron beam lithography.

19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol