Weak-value-based metrology surpasses classical limit

(Phys.org)—When measuring very small physical effects, such as the deflection of a light beam, the very act of measuring can affect the measurement outcome. Now in a new study, physicists have experimentally demonstrated that a method designed to address this problem, called weak-value-based measurement, can, when strengthened by a recently proposed technique called power recycling, surpass the classical measurement limit and offer significant advantages for making ultra-precise quantum measurements.