Quantum union bounds for sequential projective measurements

TL;DR

This paper introduces two new quantum union bounds for sequential projective measurements, providing estimates on disturbance and outcome probabilities, with potential applications in quantum communication, state discrimination, and algorithms.

Contribution

The paper presents novel quantum union bounds based on a trigonometric representation, advancing the analysis of sequential measurements in quantum information theory.

Findings

Bounds estimate disturbance accumulation in sequential measurements

Bounds predict outcome probabilities in quantum measurement sequences

Applicable to quantum communication and state discrimination tasks

Abstract

We present two new quantum union bounds for sequential projective measurements. These bounds estimate the disturbance accumulation and probability of outcomes when the measurements are performed sequentially. These results are based on a trigonometric representation of quantum states and should have wide application in quantum information theory for information processing tasks such as communication and state discrimination, and perhaps even in the analysis of quantum algorithms.