Efficiently computing the Uhlmann fidelity for density matrices

TL;DR

This paper introduces a simplified and more efficient method for computing the Uhlmann fidelity between density matrices, significantly reducing computational time for large matrices.

Contribution

The authors derive an alternative formula for Uhlmann fidelity that is easier to evaluate numerically, improving efficiency over existing methods.

Findings

Achieved a tenfold reduction in computation time for large matrices.

Provided a new formula that simplifies numerical evaluation of fidelity.

Demonstrated practical efficiency improvements in quantum information calculations.

Abstract

We consider the problem of efficiently computing the Uhlmann fidelity in the case when explicit density matrix descriptions are available. We derive an alternative formula which is simpler to evaluate numerically, saving a factor of 10 in time for large matrices.