Weak measurements with completely mixed probe states

TL;DR

This paper demonstrates that completely mixed probe states can be effectively used in weak measurements, especially under noisy conditions, and experimentally verifies this with unpolarized light for polarization rotation.

Contribution

It introduces the use of completely mixed states as probes in weak measurements and shows their noise tolerance advantages.

Findings

Completely mixed states can serve as effective probes for imaginary weak values.

Unpolarized light can be used to perform weak measurements of polarization rotation.

The approach offers robustness against noise in the probe system.

Abstract

Weak measurements with mixed probe states were investigated in the presence of noise in the probe system. We show that the completely mixed state can be used as a probe state for weak measurements of imaginary weak values. The completely mixed probe state has some advantages in terms of noise tolerance. We also experimentally demonstrated weak measurements of polarization rotation via unpolarized light, which corresponds to weak measurements with completely mixed probe states in a two-state system.