On the Sharpness and Bias of Quantum Effects

TL;DR

This paper investigates how to quantify the sharpness and bias of quantum effects, revealing their roles in joint measurability and coexistence, and introduces measures for bias with illustrative examples.

Contribution

It introduces measures for bias in quantum effects and explores their impact on joint measurability, advancing understanding of quantum effect properties.

Findings

Bias affects joint measurability of effects

Measures of bias are defined and exemplified

Sharpness and bias are key to quantum effect coexistence

Abstract

The question of quantifying the sharpness (or unsharpness) of a quantum mechanical effect is investigated. Apart from sharpness, another property, bias, is found to be relevant for the joint measurability or coexistence of two effects. Measures of bias will be defined and examples given.