Spin measurement retrodiction revisited

TL;DR

This paper revisits the problem of retrodicting spin measurements along multiple axes, providing explicit measurement operators and quantum networks for specific cases, enhancing understanding of quantum measurement inference.

Contribution

It introduces explicit measurement operators and quantum networks for retrodicting spin measurements along three and four axes, including the Vaidman-Aharonov-Albert scenario.

Findings

Explicit measurement operators for three and four axes

Quantum networks constructed for different initial Bell states

Enhanced understanding of spin measurement retrodiction

Abstract

The retrodiction of spin measurements along a set of different axes is revisited in detail. The problem is presented in two different pictures, a geometric and a general algebraic one. Explicit measurement operators that allow the retrodiction are given for the case of three and four axes. For the Vaidman-Aharanov-Albert case of three orthogonal axes the quantum network is constructed for two different initial Bell states.