Pushing the limits in real-time measurements of quantum dynamics

TL;DR

This paper introduces a factorial cumulant-based evaluation scheme that significantly reduces errors in real-time quantum dynamics measurements, enabling more accurate analysis of random telegraph signals in various scientific fields.

Contribution

The authors develop and validate a factorial cumulant method that enhances the accuracy of real-time quantum measurements by mitigating systematic and statistical errors.

Findings

Error reduction by orders of magnitude using factorial cumulants

Theoretical framework supporting error resilience

Experimental validation with single-electron tunnelling data

Abstract

Time-resolved studies of quantum systems are the key to understand quantum dynamics at its core. The real-time measurement of individual quantum numbers as they switch between certain discrete values, well known as random telegraph signal, is expected to yield maximal physical insight. However, the signal suffers from both systematic errors, such as a limited time resolution and noise from the measurement apparatus, as well as statistical errors due to a limited amount of data. Here we demonstrate that an evaluation scheme based on factorial cumulants can reduce the influence of such errors by orders of magnitude. The error resilience is supported by a general theory for the detection errors as well as experimental data of single-electron tunnelling through a self-assembled quantum dot. Thus, factorial cumulants push the limits in the analysis of random telegraph data which represent a wide class of experiments in physics, chemistry, engineering and life sciences.