Correlation Measurement of an unknown state with Weak Coupling

TL;DR

This paper introduces a method to measure correlations in unknown quantum states using weak coupling and ancillary systems, eliminating the need for classical communication or complex calculations.

Contribution

The paper presents a novel model for quantum correlation measurement that works without prior state knowledge or classical communication, relying solely on weak coupling and ancillary systems.

Findings

Correlation measurement without classical communication

Applicable to particles owned by different parties

Demonstrated with a detailed example

Abstract

Traditionally, quantum state correlation can be obtained with calculations on a state density matrix already known. Here, we propose a model with which correlations of unknown quantum states can be obtained. There are no needs of classical communication in the course of coupling, optimization and complicated calculations. All we need are weak coupling and ancillary systems. We detail the model on the state in which particles belong to the different owners. A concisely example is elaborated in the last part of this paper.