author={Thiago Werlang and G. A. P. Ribeiro and Gustavo Rigolin},
  journal={International Journal of Modern Physics B},
We review the main results and ideas showing that quantum correlations at finite temperatures (T), in particular quantum discord, are useful tools in characterizing quantum phase transitions (QPT) that only occur, in principle, at the unattainable absolute zero temperature. We first review some interesting results about the behavior of thermal quantum discord for small spin-1/2 chains and show that they already give us important hints of the infinite chain behavior. We then study in detail and… 
15 Citations
Quantum correlation and quantum phase transition in the one-dimensional extended Ising model
By analyzing the divergent behaviors of quantum discord at the critical points, it is found that the quantum phase transitions driven by different parameters of the model can also display distinctive critical behaviors, which provides a scheme to detect the topological quantum phase transition in practice.
Quantum and Classical Thermal Correlations in Spin-1 Heisenberg Chain with Alternating Single-Ion Anisotropy
In the present paper, we study the quantum phase transition in a spin-1 Heisenberg model with two and three particles by using pairwise classical and quantum thermal correlations and entanglement
Quantum Discord in the Ground State of Spin Chains
The ground state of a quantum spin chain is a natural playground for investigating correlations. Nevertheless, not all correlations are genuinely of quantum nature. Here we review the recent progress
Does “cooling by heating” protect quantum correlations?
It is found that at both zero and finite temperature, depending on the parameters used, quantum correlations can be enhanced even when increasing the damping rates, a somewhat counterintuitive result.
Pairwise thermal entanglement and quantum discord in a three-ligand spin-star structure
In this work, we perform a comparative study between the pairwise thermal entanglement (PWTE) and thermal quantum discord (TQD) to detect quantum phase transitions (QPT)s in a three-ligand spin-star
Quantum correlations in a few-atom spin-1 Bose–Hubbard model
We study the thermal quantum correlations and entanglement in the spin-1 Bose–Hubbard model with two and three particles. While we use negativity to calculate entanglement, more general non-classical
In- and out-of-equilibrium quantum metrology with mean-field quantum criticality.
The single spherical quantum spin (SQS) serves as stereotypical toy model that allows analytical insights on a mean-field level and the quantum Fisher information is obtained analytically, which is associated with the minimum lower bound for the precision of estimation of the parameter driving the phase transition.
2 Low-Dimensional Quantum Spin Systems 1 . 2 . 1 Quantum Spin Models
  • Physics
  • 2016
Magnetism as a physical phenomenon has been known since antiquity but it was only after the advent of quantum mechanics that modern, microscopic theories of magnetism could be developed. Magnetism is


Quantum correlations in spin chains at finite temperatures and quantum phase transitions.
It is shown that QD spotlight the critical points associated with quantum phase transitions (QPT) for this model even at finite T, which may have important implications for experimental characterization of QPTs when one is unable to reach temperatures below which a QPT can be seen.
Spotlighting quantum critical points via quantum correlations at finite temperatures
We extend the program initiated by T. Werlang et al. [Phys. Rev. Lett. 105, 095702 (2010)] in several directions. Firstly, we investigate how useful quantum correlations, such as entanglement and
Classical correlation and quantum discord in critical systems
We discuss the behavior of quantum and classical pairwise correlations in critical systems, with the quantumness of the correlations measured by the quantum discord. We analytically derive these
Quantum and classical thermal correlations in the XY spin-(1/2) chain
We investigate pairwise quantum correlation as measured by the quantum discord as well as its classical counterpart in the thermodynamic limit of anisotropic XY spin-1/2 chains in a transverse
Scaling of entanglement close to a quantum phase transition
It is demonstrated, for a class of one-dimensional magnetic systems, that entanglement shows scaling behaviour in the vicinity of the transition point, which connects the theory of critical phenomena with quantum information by exploring the entangling resources of a system close to its quantum critical point.
Entanglement in quantum critical phenomena.
The results establish a precise connection between concepts of quantum information, condensed matter physics, and quantum field theory, by showing that the behavior of critical entanglement in spin systems is analogous to that of entropy in conformal field theories.
Ground-state factorization and correlations with broken symmetry
We show how the phenomenon of factorization in a quantum many-body system is of collective nature. To this aim we study the quantum discord Q in the one-dimensional XY model in a transverse field. We
Quantum discord and quantum phase transition in spin chains
Quantum phase transitions of the transverse Ising and antiferromagnetic $XXZ$ spin $S=1/2$ chains are studied using quantum discord. Quantum discord allows the measure of quantum correlations present
Entanglement and local extremes at an infinite-order quantum phase transition
The characterization of an infinite-order quantum phase transition (QPT) by entanglement measures is analyzed. To this aim, we consider two closely related solvable spin-1/2 chains, namely, the
Reexamination of entanglement and the quantum phase transition
We show that, for an exactly solvable quantum spin model, a discontinuity in the first derivative of the ground-state concurrence appears in the absence of a quantum phase transition. It is opposed