Berlin 2014 – scientific programme

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A: Fachverband Atomphysik

A 16: Symposium SAMOP Dissertation-Prize 2014 SYAD (with Q, MO, P)

A 16.4: Invited Talk

Tuesday, March 18, 2014, 12:00–12:30, Audimax

One step beyond entanglement: general quantum correlations and their role in quantum information theory — •Alexander Streltsov — ICFO - The Institute of Photonic Sciences, Castelldefels, Spain

Quantum entanglement is by far the most famous kind of quantum correlations and its fundamental role in several tasks in quantum information theory is undeniable. However, recent discoveries suggest that entanglement is not always necessary: a quantum computer can outperform its classical counterpart even without any entanglement. This and related examples demonstrate the limits of the concept of entanglement and suggest the formulation of more general quantum correlations which are more suitable for the tasks under study. Quantum discord is the most famous measure of such general quantum correlations beyond entanglement. In this talk we discuss the role of quantum discord in the quantum measurement process and in the task of entanglement distribution. In particular, we show that quantum discord is the essential resource for this task: the distribution of any finite amount of entanglement requires the transmission of at least the same amount of discord. Our results also reveal optimal distribution protocols even if the exchanged particle exhibits no entanglement with the rest of the system.