Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Colloquium: Physics of optical lattice clocks   Recently invented and demonstrated, optical lattice clocks hold great promise
for improving the precision of modern timekeeping. These clocks aim at the
10^-18 fractional accuracy, which translates into a clock that would neither
lose or gain a fraction of a second over an estimated age of the Universe. In
these clocks, millions of atoms are trapped and interrogated simultaneously,
dramatically improving clock stability. Here we discuss the principles of
operation of these clocks and, in particular, a novel concept of "magic"
trapping of atoms in optical lattices. We also highlight recently proposed
microwave lattice clocks and several applications that employ the optical
lattice clocks as a platform for precision measurements and quantum information
processing.

5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat