Experimental investigation of high-efficiency weak-value amplification of nonunitary evolution

Abstract

High-sensitivity metrology plays an important role in parameter estimation, and weak-value amplification is a significant tool used to enhance sensitivity. However, the efficiency of weak-value amplification is always affected by the postselection probability and meter loss. In this article we report on the realization of a device for weak interaction that realizes the nonunitary evolution based on a spatial light modulator and applies the weak-value amplification of nonunitary evolution. The weak-value amplification of nonunitary evolution can achieve efficiency nearly ninefold that of unitary evolution experimentally under specific settings, because of the quadratic relation between the meter shift and the norm of the weak value $|{A}_{w}|$. This work demonstrates the superiority of nonunitary evolution in weak-value amplification, provides an experimental scheme of weak interaction for other forms of nonunitary evolution, and possesses the potential to be combined with other techniques for higher efficiency.