On Estimation of Fully Entangled Fraction

TL;DR

This paper investigates the fully entangled fraction (FEF) of mixed quantum states, deriving new upper bounds that improve estimation accuracy, especially for weakly mixed states.

Contribution

The paper introduces novel upper bounds for FEF, enhancing the precision of its estimation for mixed quantum states, particularly in the weakly mixed regime.

Findings

New upper bounds for FEF are derived.

Upper bounds are tight for weakly mixed states.

Estimation of FEF is improved with these bounds.

Abstract

We study the fully entangled fraction (FEF) of arbitrary mixed states. New upper bounds of FEF are derived. These upper bounds make complements on the estimation of the value of FEF. For weakly mixed quantum states, an upper bound is shown to be very tight to the exact value of FEF.