Preparing tunable Bell-diagonal states on a quantum computer

TL;DR

This paper introduces a quantum circuit for preparing tunable Bell-diagonal states on a quantum computer, demonstrating its application in measuring various quantum correlations and coherence in Werner states.

Contribution

It presents a novel, tunable quantum circuit for preparing Bell-diagonal states and demonstrates its implementation on IBM Q hardware for analyzing quantum correlations.

Findings

Successful implementation of the circuit on IBM Q 5 Yorktown.

Measurement of quantum correlations and coherence in Werner states.

Validation of the circuit's tunability and effectiveness.

Abstract

The class of two-qubit Bell-diagonal states has been the workhorse for developing understanding about the geometry, dynamics, and applications of quantum resources. In this article, we present a quantum circuit for preparing Bell-diagonal states on a quantum computer in a tunable way. We implement this quantum circuit using the IBM Q 5 Yorktown quantum computer and, as an application example, we measure the non-local, steering, entanglement, and discord quantum correlations and non-local quantum coherence of Werner states.