A remark on the paper ``Randomizing quantum states: Constructions and applications''

Abstract

The concept of $\e$-randomizing quantum channels has been introduced by Hayden, Leung, Shor and Winter in connection with approximately encrypting quantum states. They proved using a discretization argument that sets of roughly $d\log d$ random unitary operators provide examples of such channels on $\C^d$. We show that a simple trick improves the efficiency of the argument and reduces the number of unitary operators to roughly $d$.

References in corpus (1)

• Randomizing quantum states: Constructions and applications