Entanglement detection on an NMR quantum information processor using random local measurements

TL;DR

This paper demonstrates that a small set of random local measurements can effectively detect bipartite entanglement in two-qubit and hybrid quantum systems using NMR, validated by quantum state tomography.

Contribution

The study experimentally verifies that three random local measurements suffice for entanglement detection on a two-qubit NMR system and extends the approach to a hybrid 2x3 system.

Findings

Three random local measurements detect two-qubit entanglement effectively.

The scheme successfully witnesses entanglement across various states.

Simulation shows potential for optimal entanglement detection in hybrid systems.

Abstract

Random local measurements have recently been proposed to construct entanglement witnesses and thereby detect the presence of bipartite entanglement. We experimentally demonstrate the efficacy of one such scheme on a two-qubit NMR quantum information processor. We show that a set of three random local measurements suffices to detect the entanglement of a general two-qubit state. We experimentally generate states with different amounts of entanglement, and show that the scheme is able to clearly witness entanglement. We perform complete quantum state tomography for each state and compute state fidelity to validate our results. Further, we extend previous results and perform a simulation using random local measurements to optimally detect bipartite entanglement in a hybrid system of $2\otimes 3$ dimensionality.