Classical correlation alone supplies the anomaly to weak values

TL;DR

This paper demonstrates that classical correlations alone can produce anomalous weak values, challenging the notion that such phenomena are exclusively quantum and providing an operational, model-independent perspective.

Contribution

It introduces an operational definition of anomalous weak values and shows they can arise purely from classical correlations, not necessarily quantum effects.

Findings

Classical correlations can produce anomalous weak values.

Anomalous weak values are not uniquely quantum phenomena.

A simple classical example without disturbance is provided.

Abstract

The question of what is genuinely quantum about weak values is only ever going to elicit strongly subjective opinions---it is not a scientific question. Good questions, when comparing theories, are operational---they deal with the unquestionable outcomes of experiment. We give the anomalous shift of weak values an objective meaning through a generalization to an operational definition of anomalous post-selected averages. We show the presence of these averages necessitate correlations in every model giving rise to them---quantum or classical. Characterizing such correlations shows that they are ubiquitous. We present the simplest classical example without the need of disturbance realizing these generalized anomalous weak values.