A first step towards quantum algorithms: Minimizing the guesswork of a quantum ensemble

A quantum ensemble — a set of quantum states with their corresponding probabilities — is essential to the encoding of classical information for transmission over quantum channels. But receivers must be able to ‘guess’ the transmitted quantum state, incurring a cost called ‘guesswork.’ Recently, researchers have derived analytical solutions of the guesswork problem for when the ensemble is subject to a finite set of conditions. The results constitute a first step towards future algorithms for quantum software.