Quantum discord in a spin system with symmetry breaking

Abstract

We analyze the quantum discord Q throughout the low-temperature phase diagram of the quantum XY model in transverse field. We first focus on the T=0 order-disorder quantum phase transition both in the symmetric ground state and in the symmetry broken one. Besides it, we highlight how Q displays clear anomalies also at a non critical value of the control parameter inside the ordered phase, where the ground state is completely factorized. We evidence how the phenomenon is in fact of collective nature and displays universal features. We also study Q at finite temperature. We show that, close to the quantum phase transition, Q exhibits quantum-classical crossover of the system with universal scaling behavior. We evidence a non trivial pattern of thermal correlations resulting from the factorization phenomenon.

9 pages, 9 figure, Contribution to the Festschrift volume in honour of Vladimir Korepin

References in corpus (12)

• Quantum discord and quantum phase transition in spin chains
• Bipartite entanglement and entropic boundary law in lattice spin systems
• Entanglement and factorized ground states in two-dimensional quantum antiferromagnets
• Divergence of the entanglement range in low dimensional quantum systems
• Theory of ground state factorization in quantum cooperative systems
• Fidelity analysis of topological quantum phase transitions
• Separability and ground state factorization in quantum spin systems
• Two-spin entanglement distribution near factorized states
• Symmetry breaking effects upon bipartite and multipartite entanglement in the XY model
• Ground-state factorization and quantum phase transition in dimerized spin chains
• Reading entanglement in terms of spin configurations in quantum magnets
• Enhancement of pairwise entanglement from $\mathbbm{Z}_2$ symmetry breaking

Cited by in corpus (15)

• The classical-quantum boundary for correlations: discord and related measures
• Measures and applications of quantum correlations
• Quantum coherence and uncertainty in the anisotropic XY chain
• Global quantum correlations in finite-size spin chains
• Factorization and Criticality in the Anisotropic XY Chain via Correlations
• Criticality, factorization and long-range correlations in the anisotropic XY-model
• Genuine Multipartite Entanglement Trends in Gapless-gapped Transitions of Quantum Spin Systems
• Quantum discord in the ground state of spin chains
• Exact dynamics of quantum correlations of two qubits coupled to bosonic baths
• Magnetic quantum correlation in the 1D transverse-field XXZ model
• Dynamical quantum correlations after sudden quenches
• Mutual information and spontaneous symmetry breaking
• Static and dynamical quantum correlations in phases of an alternating field XY model
• Quantum Correlation with Sandwiched Relative Entropies: Advantageous as Order Parameter in Quantum Phase Transitions
• Shared Purity of Multipartite Quantum States