Random measurements are almost maximally incompatible

TL;DR

This paper studies the incompatibility of random quantum measurements, showing that certain classes are nearly maximally incompatible, using advanced mathematical tools like random matrices and free probability.

Contribution

It demonstrates that random dichotomic projective and basis measurements are nearly maximally incompatible, extending understanding of quantum measurement incompatibility.

Findings

Random dichotomic projective measurements are nearly maximally incompatible.

Random basis measurements are nearly maximally incompatible.

Uses incompatibility witnesses, random matrices, and free probability techniques.

Abstract

In this work, we investigate the incompatibility of random quantum measurements. Most previous work has focused on characterizing the maximal amount of white noise that any fixed number of incompatible measurements with a fixed number of outcomes in a fixed dimension can tolerate before becoming compatible. This can be used to quantify the maximal amount of incompatibility available in such systems. The present article investigates the incompatibility of several classes of random measurements, i.e., the generic amount of incompatibility available. In particular, we show that for an appropriate choice of parameters, both random dichotomic projective measurements and random basis measurements are close to being maximally incompatible. We use the technique of incompatibility witnesses to certify incompatibility and combine it with tools from random matrices and free probability.