Unambiguous discrimination between two unknown qudit states

TL;DR

This paper investigates the optimal unambiguous discrimination between two unknown qudit states, revealing that success probability is independent of the system's dimension and proposing a practical implementation scheme.

Contribution

It demonstrates that the success probability for discriminating unknown qudit states is dimension-independent and provides a feasible scheme for physical implementation.

Findings

Success probability is independent of the dimension n.

A scheme for physical implementation of the programmable state discriminator.

Optimal discrimination achieved with known success probability.

Abstract

We consider the unambiguous discrimination between two unknown qudit states in $n$-dimensional ($n\geqslant2$) Hilbert space. By equivalence of unknown pure states to known mixed states and with the Jordan-basis method, we demonstrate that the optimal success probability of the discrimination between two unknown states is independent of the dimension $n$. We also give a scheme for a physical implementation of the programmable state discriminator that unambiguously discriminate between two unknown states with optimal probability of success.