Universality of local weak interactions and its application for interferometric alignment

TL;DR

This paper demonstrates a universal property of local weak interactions in pre- and postselected quantum particles, enabling a novel interferometric alignment method that efficiently characterizes beam misalignments through local interaction effects.

Contribution

It introduces the concept of universality in local weak interactions for pre- and postselected particles and applies it to develop an efficient interferometric alignment technique.

Findings

Confirmed universality of local weak interactions experimentally.

Developed an interferometric alignment method using a single detector.

Achieved precise beam misalignment characterization through local interaction effects.

Abstract

The modification of the effect of interactions of a particle as a function of its pre- and postselected states is analyzed theoretically and experimentally. The universality property of this modification in the case of local interactions of a spatially pre- and postselected particle has been found. It allowed to define an operational approach for characterization of the presence of a quantum particle in a particular place: the way it modifies the effect of local interactions. The experiment demonstrating this universality property provides an efficient interferometric alignment method, in which the beam on a single detector throughout one phase scan yields all misalignment parameters.