Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy decay and frequency shift of a superconducting qubit from
  non-equilibrium quasiparticles   Quasiparticles are an important decoherence mechanism in superconducting
qubits, and can be described with a complex admittance that is a generalization
of the Mattis-Bardeen theory. By injecting non-equilibrium quasiparticles with
a tunnel junction, we verify qualitatively the expected change of the decay
rate and frequency in a phase qubit. With their relative change in agreement to
within 4% of prediction, the theory can be reliably used to infer quasiparticle
density. We describe how settling of the decay rate may allow determination of
whether qubit energy relaxation is limited by non-equilibrium quasiparticles.

33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an