Local trade-off between information and disturbance in quantum measurements

TL;DR

This paper investigates the local trade-off between information gain and disturbance in quantum measurements, revealing that while they generally correlate, it is possible to optimize measurements to increase information while reducing disturbance.

Contribution

It introduces a general scheme to enhance information gain while decreasing disturbance in quantum measurements with imperfect correlations.

Findings

Correlation between information and disturbance is generally positive.

It is possible to increase information while decreasing disturbance.

A scheme is proposed for measurements with imperfect correlation.

Abstract

This study confirms a local trade-off between information and disturbance in quantum measurements. It is represented by the correlation between the changes in these two quantities when the measurement is slightly modified. The correlation indicates that when the measurement is modified to increase the obtained information, the disturbance also increases in most cases. However, the information can be increased while decreasing the disturbance because the correlation is not necessarily perfect. For measurements having imperfect correlations, this paper discusses a general scheme that raises the amount of information while decreasing the disturbance.