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arXiv · 1806.05747

Probing entanglement entropy via randomized measurements

Tiff Brydges·Andreas Elben·Petar Jurcevic·Benoît Vermersch·Christine Maier·Ben P. Lanyon·Peter Zoller·Rainer Blatt·Christian F. Roos
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Abstract

Entanglement is the key feature of many-body quantum systems, and the development of new tools to probe it in the laboratory is an outstanding challenge. Measuring the entropy of different partitions of a quantum system provides a way to probe its entanglement structure. Here, we present and experimentally demonstrate a new protocol for measuring entropy, based on statistical correlations between randomized measurements. Our experiments, carried out with a trapped-ion quantum simulator, prove the overall coherent character of the system dynamics and reveal the growth of entanglement between its parts - both in the absence and presence of disorder. Our protocol represents a universal tool for probing and characterizing engineered quantum systems in the laboratory, applicable to arbitrary quantum states of up to several tens of qubits.

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Tiff Brydges, Andreas Elben, Petar Jurcevic, Benoît Vermersch, Christine Maier, Ben P. Lanyon, Peter Zoller, Rainer Blatt, Christian F. Roos. 2018-06-14. Probing entanglement entropy via randomized measurements. https://doi.org/10.1126/science.aau4963

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