Unambiguous discrimination of extremely similar states by a weak measurement

TL;DR

This paper introduces a weak measurement-based method for unambiguously discriminating extremely similar quantum states, achieving optimal success probability while offering improved error tolerance over conventional techniques.

Contribution

The paper presents a novel weak measurement protocol that reaches the Ivanovic-Dieks-Peres limit for state discrimination with enhanced error tolerance.

Findings

Achieves optimal discrimination probability for similar states

Provides better success-to-error ratio than traditional methods

Demonstrates robustness against measurement errors

Abstract

In this paper, we propose a method to discriminate two extremely similar quantum states via a weak measurement. For the two states with equal prior probabilities, the optimum discrimination probability given by Ivanovic-Dieks-Peres limit can be achieved by our protocol with an appropriate choice of the interaction strength. However, compared with the conventional method for state discrimination, our approach shows the advantage of error-tolerance by achieving a better ratio of the success probability to the probability of error.