Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ion-trap simulation of the quantum phase transition in an exactly
  solvable model of spins coupled to bosons   It is known that arrays of trapped ions can be used to efficiently simulate a
variety of many-body quantum systems. Here, we show how it is possible to build
a model representing a spin chain interacting with bosons which is exactly
solvable. The exact spectrum of the model at zero temperature and the ground
state properties are studied. We show that a quantum phase transition occurs
when the coupling between spins and bosons reaches a critical value, which
corresponds to a level crossing in the energy spectrum. Once the critical point
is reached, the number of bosonic excitations in the ground state, which can be
assumed as an order parameter, starts to be different from zero. The population
of the bosonic mode is accompanied by a macroscopic magnetization of the spins.
This double effect could represent an useful resource for the phase transition
detection since a measure on the phonon can give information about the phase of
the spin system. A finite temperature phase diagram is also given in the
adiabatic regime.

25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc