Probing entanglement entropy via randomized measurements

Understand

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.