Reversible Projective Measurement in Quantum Ensembles

TL;DR

This paper demonstrates an experimental method using NMR to perform reversible projective measurements on quantum ensembles, enabling information extraction without destroying the quantum state, which could advance quantum information processing.

Contribution

It introduces a novel reversible measurement scheme utilizing reversible dynamics and weak measurements, demonstrated experimentally with 133Cs nuclei in liquid crystals.

Findings

Reversible projective measurement scheme successfully implemented.

Minimal disturbance to quantum states achieved.

Potential applications in quantum information processing.

Abstract

We present experimental NMR demonstration of a scheme of reversible projective measurement, which allows extracting information on outcomes and probabilities of a projective measurement in a non-destructive way, with a minimal net effect on the quantum state of an ensemble. The scheme uses reversible dynamics and weak measurement of the intermediate state. The experimental system is an ensemble of 133Cs (S = 7/2) nuclei in a liquid-crystalline matrix.