Global quantum correlations in finite-size spin chains
S Campbell
(Quantum Systems Unit, Okinawa Institute of Science and Technology Graduate University , 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; Department of Physics, University College Cork , Republic of Ireland)
L Mazzola
(Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University , Belfast BT7 1NN, UK)
G De Chiara
(Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University , Belfast BT7 1NN, UK)
T J G Apollaro
(Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University , Belfast BT7 1NN, UK; Dipartimento di Fisica, Università della Calabria , 87036 Arcavacata di Rende (CS), Italy; INFN—Gruppo collegato di Cosenza, Italy)
F Plastina
(Dipartimento di Fisica, Università della Calabria , 87036 Arcavacata di Rende (CS), Italy; INFN—Gruppo collegato di Cosenza, Italy)
Th Busch
(Quantum Systems Unit, Okinawa Institute of Science and Technology Graduate University , 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan; Department of Physics, University College Cork , Republic of Ireland)
M Paternostro
(Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen's University , Belfast BT7 1NN, UK)
Journal: New Journal of Physics
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• IOP Publishing
• ISSN: 1367-2630
Abstract
We perform an extensive study of the properties of global quantum correlations in finite-size one-dimensional quantum spin models at finite temperature. By adopting a recently proposed measure for global quantum correlations (Rulli and Sarandy 2011 Phys. Rev. A 84 042109), called global discord , we show that critical points can be neatly detected even for many-body systems that are not in their ground state. We consider the transverse Ising model, the cluster-Ising model where three-body couplings compete with an Ising-like interaction, and the nearest-neighbor XX Hamiltonian in transverse magnetic field. These models embody our canonical examples showing the sensitivity of global quantum discord close to criticality. For the Ising model, we find a universal scaling of global discord with the critical exponents pertaining to the Ising universality class.
S Campbell, L Mazzola, G De Chiara, et al. (2013). "Global quantum correlations in finite-size spin chains". New Journal of Physics. https://doi.org/10.1088/1367-2630/15/4/043033