Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Determination of the fine structure constant with atom interferometry
  and Bloch oscillations   We use Bloch oscillations to transfer coherently many photon momenta to
atoms. Then we can measure accurately the recoil velocity $\hbar k/m$ and
deduce the fine structure constant $\alpha$. The velocity variation due to
Bloch oscillations is measured using atom interferometry. This method yields to
a value of the fine structure constant $\alpha^{-1}= 137.035 999 45 (62)$ with
a relative uncertainty of about $4.5 \times 10^{-9}$.

30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con