Does Measurement Necessarily Destroy Coherence?

TL;DR

This paper investigates whether quantum measurements necessarily destroy coherence, proposing that certain experiments with entangled states can differentiate between measurement types and test the preservation of coherence.

Contribution

It demonstrates that experiments with maximally entangled bipartite states can distinguish between projective and unitary measurements, challenging the notion that measurement always destroys coherence.

Findings

Experiments can differentiate measurement types based on coherence preservation.

Unitarity of measurement processes can be tested with entangled states.

Measurement may not always result in coherence destruction.

Abstract

It has been proposed that measurement in quantum mechanics results from spontaneous breaking of a symmetry of the measuring apparatus and could be a unitary process that preserves coherence. Viewed in this manner, it is argued, non-destructive measurements should preserve this coherence and be reversible. It is shown that experiments with maximally entangled bipartite states can indeed distinguish between projective and unitary measurements.