Precision measurements are important across all fields of science but they are especially critical to quantum research. Optical phase measurements – which can be used to measure distance, position, displacement, acceleration, and optical path length – are of particular interest.

Quantum entanglement enables higher precision estimates than would otherwise be possible and we have demonstrated an optical phase measurement with an entangled four-photon interference visibility greater than the threshold required to beat the standard quantum limit.

These results lead the way to new high-precision measurement applications.

For further information on research of this kind at the University of Bristol, please visit the Quantum Engineering Technology Labs website.