Calculating spin correlations with a quantum computer

TL;DR

This paper demonstrates calculating spin correlation functions using IBM quantum processors, showcasing quantum properties and providing an educational platform for remote learning of quantum mechanics and circuit design.

Contribution

It introduces a practical method for computing spin correlations on real quantum hardware, highlighting quantum properties and educational applications.

Findings

Confirmed rotational invariance of the singlet state

Observed interesting properties of triplet states

Identified surprising features of three-qubit entangled states

Abstract

We calculate spin correlation functions using IBM quantum processors, accessed online. We demonstrate the rotational invariance of the singlet state, interesting properties of the triplet states, and surprising features of a state of three entangled qubits. This exercise is ideal for remote learning and generates data with real quantum mechanical systems that are impractical to investigate in the local laboratory. Students learn a wide variety of skills, including calculation of multipartite spin correlation functions, design and analysis of quantum circuits, and remote measurement with real quantum processors.