1,312 research outputs found
Measurement-induced nonlocality based on the relative entropy
We quantify the measurement-induced nonlocality [Luo and Fu, Phys. Rev. Lett.
106, 120401 (2011)] from the perspective of the relative entropy. This
quantification leads to an operational interpretation for the
measurementinduced nonlocality, namely, it is the maximal entropy increase
after the locally invariant measurements. The relative entropy of nonlocality
is upper bounded by the entropy of the measured subsystem. We establish a
relationship between the relative entropy of nonlocality and the geometric
nonlocality based on the Hilbert- Schmidt norm, and show that it is equal to
the maximal distillable entanglement. Several trade-off relations are obtained
for tripartite pure states. We also give explicit expressions for the relative
entropy of nonlocality for Bell-diagonal states.Comment: 5 pages, 1 figures, version accepted Phys. Rev. A, PHYSICAL REVIEW A
85, 042325 (2012
Factorization and Criticality in the Anisotropic XY Chain via Correlations
In this review, we discuss the zero and finite temperature behavior of
various bipartite quantum and total correlation measures, the skew
information-based quantum coherence, and the local quantum uncertainty in the
thermal ground state of the one-dimensional anisotropic XY model in transverse
magnetic field. We compare the ability of considered measures to correctly
detect or estimate the quantum critical point and the non-trivial factorization
point possessed by the spin chain.Comment: 29 pages, 8 figures. A review paper accepted for publication in the
special issue Entanglement Entropy in the journal Entrop
Genuine quantum correlations in quantum many-body systems: a review of recent progress
Quantum information theory has considerably helped in the understanding of
quantum many-body systems. The role of quantum correlations and in particular,
bipartite entanglement, has become crucial to characterise, classify and
simulate quantum many body systems. Furthermore, the scaling of entanglement
has inspired modifications to numerical techniques for the simulation of
many-body systems leading to the, now established, area of tensor networks.
However, the notions and methods brought by quantum information do not end with
bipartite entanglement. There are other forms of correlations embedded in the
ground, excited and thermal states of quantum many-body systems that also need
to be explored and might be utilised as potential resources for quantum
technologies. The aim of this work is to review the most recent developments
regarding correlations in quantum many-body systems focussing on multipartite
entanglement, quantum nonlocality, quantum discord, mutual information but also
other non classical measures of correlations based on quantum coherence.
Moreover, we also discuss applications of quantum metrology in quantum
many-body systems.Comment: Review. Close to published version. Comments are welcome! Please
write an email to g.dechiara[(at)]qub.ac.u
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