Weak measurements with a qubit meter

TL;DR

This paper develops methods to measure weak values of quantum observables using a qubit meter, emphasizing the measurement of both real and imaginary parts, with practical schemes and experimental suggestions.

Contribution

It introduces new schemes for measuring weak values with qubit meters, including direct measurement of the imaginary part, and provides compact formulas for qubit observables.

Findings

Derived measurement schemes for weak values using qubit meters

Provided formulas for weak values of single and product qubit observables

Suggested experimental implementations with cold trapped ions

Abstract

We derive schemes to measure the so-called weak values of quantum system observables by coupling of the system to a qubit meter system. We highlight, in particular, the meaning of the imaginary part of the weak values, and show how it can be measured directly on equal footing with the real part of the weak value. We present compact expressions for the weak value of single qubit observables and of product observables on qubit pairs. Experimental studies of the results are suggested with cold trapped ions.