Retrieve ‘Lost’ Information from #Quantum measurements tagged posts

Credit: CC0 Public Domain

Typically when scientists make a measurement, they know exactly what kind of measurement they’re making, and their purpose is to obtain a measurement outcome. But in an “unrecorded measurement,” both the type of measurement and the measurement outcome are unknown. Despite the fact that scientists do not know this information, experiments clearly show that unrecorded measurements unavoidably disturb the state of the system being measured for quantum (but not classical) systems. In classical systems, unrecorded measurements have no effect.

Although the information in unrecorded measurements appears to be completely lost, Prof Michael Revzen and Prof Ady Mann have described a protocol that can retrieve some of the lost information...