Weak Measurements

TL;DR

Weak measurements involve pre- and post-selection with weakened coupling, revealing weak values that uncover novel quantum phenomena and potential practical effects, enriching our understanding of quantum mechanics.

Contribution

This paper reviews the concept of weak measurements, highlighting their ability to reveal unique quantum effects through weak values and their implications for quantum theory.

Findings

Weak values can differ significantly from eigenvalues.

Weak measurements help explain peculiar quantum phenomena.

Potential practical applications of weak values are identified.

Abstract

Weak measurement is a standard measuring procedure with two changes: it is performed on pre- and post-selected quantum systems and the coupling to the measuring device is weakened. The outcomes of weak measurements, ``weak values'' are very different for the eigenvalues of the measured operators. The weak values yield novel rich structure of the quantum world. Weak values help explaining peculiar quantum phenomena and finding new effects which might have practical applications.