A classical postselected weak amplification scheme via thermal light cross-Kerr effect

TL;DR

This paper demonstrates a novel thermal light cross-Kerr effect enabling postselected weak amplification without destructive interference, revealing new insights into weak measurements and generating nonclassical light states.

Contribution

It introduces the first thermal light cross-Kerr effect and shows that weak amplification can occur without destructive interference, challenging traditional understanding.

Findings

Postselection and weak amplification can be explained classically.

Weak amplification and weak value are distinct concepts.

A nonclassical mixed light state can be generated after postselection.

Abstract

In common sense, postselected weak amplification must be related to destructive interference effect of the meter system, and a single photon exerts no effect on thermal field via cross-phasemodulation (XPM) interaction. In this Letter we present, for the first time, a thermal light cross-Kerr effect. Through analysis, we reveal two unexpected results: i) postselection and weak amplification can be explained at a classical level without destructive interference, and ii) weak amplification and weak value are not one thing. After postselection a new mixed light can be generated which is nonclassical. This scheme can be realized via electromagnetically-induced transparency.