Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simultaneous two initial clock states preparation for thulium optical
  clock   Due to the low sensitivity of the thulium optical clock to black-body
radiation and good accuracy and stability estimations, it appears to be one of
the most promising transportable optical clocks. One of the leading systematic
effects for Tm clock transition, namely the second-order Zeeman effect, can be
canceled by probing two clock transitions between different hyperfine levels of
ground and metastable states during the clock operation. We prepare the atoms
in $m_F=0$ state of both ground hyperfine levels simultaneously and excite
alternately two clock transitions. Here we demonstrate efficient optical
pumping into both target states via single-frequency radiation at 418.8 nm. The
resulting population of $m_F=0$ states of ground hyperfine levels is 36% and
3.8% of the initial number of atoms with less than 4% and 0.4% on non-zero
magnetic sublevels, correspondingly. We performed numerical simulations of the
optical pumping process which is able to explain experimental results
reasonably well.

27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom