Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Controlling long ion strings for quantum simulation and precision
  measurements   Scaling a trapped-ion based quantum simulator to a large number of ions
creates a fully-controllable quantum system that becomes inaccessible to
numerical methods. When highly anisotropic trapping potentials are used to
confine the ions in the form of a long linear string, several challenges have
to be overcome to achieve high-fidelity coherent control of a quantum system
extending over hundreds of micrometers. In this paper, we describe a setup for
carrying out many-ion quantum simulations including single-ion coherent control
that we use for demonstrating entanglement in 50-ion strings. Furthermore, we
present a set of experimental techniques probing ion-qubits by Ramsey and
Carr-Purcell-Meiboom-Gill (CPMG) pulse sequences that enable detection (and
compensation) of power-line-synchronous magnetic-field variations, measurement
of path length fluctuations, and of the wavefronts of elliptical laser beams
coupling to the ion string.

11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
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
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th