Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Decoherence of a Superposition of Macroscopic Current States in a SQUID   We show that fundamental conservation laws mandate parameter-free mechanisms
of decoherence of quantum oscillations of the superconducting current between
opposite directions in a SQUID -- emission of phonons and photons at the
oscillation frequency. The corresponding rates are computed and compared with
experimental findings. The decohering effects of external mechanical and
magnetic noise are investigated.

36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
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The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph