Detecting Entanglement of Unknown Quantum States with Random Measurements

TL;DR

This paper introduces a method for detecting entanglement in unknown quantum states using random measurements and semidefinite programming, with an adaptive measurement scheme to improve detection reliability.

Contribution

It presents a novel approach combining random local measurements and semidefinite programming to detect entanglement in unknown quantum states, with an adaptive measurement strategy.

Findings

Effective detection of entanglement with increasing measurements

Performance demonstrated on various quantum state examples

Adaptive measurement scheme improves detection success

Abstract

In quantum information theory, the reliable and effective detection of entanglement is of paramount importance. However, given an unknown state, assessing its entanglement is a challenging task. To attack this problem, we investigate the use of random local measurements, from which entanglement witnesses are then constructed via semidefinite programming methods. We propose a scheme of successively increasing the number of measurements until the presence of entanglement can be unambiguously concluded, and investigate its performance in various examples.