A new approach to measure quantum entanglement in multiparticle systems. This is the key outcome of a study conducted by SISSA, ICTP and IQOQI-Innsbruck recently published in Nature Physics.
Entanglement is a crucial characteristic for understanding quantum systems and for developing quantum technologies. While it can be easily measured in case of individual particles – whether protons, atoms or molecules – probing entanglement in larger and larger systems becomes quickly prohibitive. The investigators led by physicist Marcello Dalmonte, recently awarded with a starting grant on this topic from the European Research Council, are proposing a completely innovative approach. Rather than studying the features of the system of interest, they are suggesting to create and analyze new systems governed by entanglement properties directly connected to the original ones, but easier to quantify experimentally. Thus, a challenging problem turns into a well-established laboratory practice that can be carried-out in several experimental conditions, from atomic systems to superconducting circuits.