Experimental high-dimensional Greenberger-Horne-Zeilinger entanglement with superconducting transmon qutrits

TL;DR

This paper reports the experimental creation and certification of a high-dimensional three-partite entangled state (qutrit GHZ state) using superconducting transmon qubits, demonstrating the platform's capability for complex quantum entanglement.

Contribution

The first experimental demonstration of high-dimensional multipartite entanglement in a superconducting quantum processor, expanding the capabilities of superconducting platforms beyond binary quantum states.

Findings

Achieved 76% fidelity in generating a three-qutrit GHZ state.

Demonstrated high-dimensional entanglement certification in superconducting systems.

Showed superconducting devices can be used for complex high-dimensional quantum experiments.

Abstract

Multipartite entanglement is one of the core concepts in quantum information science with broad applications that span from condensed matter physics to quantum physics foundations tests. Although its most studied and tested forms encompass two-dimensional systems, current quantum platforms technically allow the manipulation of additional quantum levels. We report the experimental demonstration and certification of a high-dimensional multipartite entangled state in a superconducting quantum processor. We generate the three-qutrit Greenberger-Horne-Zeilinger state by designing the necessary pulses to perform high-dimensional quantum operations. We obtain the fidelity of $76\pm 1\%$, proving the generation of a genuine three-partite and three-dimensional entangled state. To this date, only photonic devices have been able to create and certify the entanglement of these high-dimensional states. Our work demonstrates that another platform, superconducting systems, is ready to exploit genuine high-dimensional entanglement and that a programmable quantum device accessed on the cloud can be used to design and execute experiments beyond binary quantum computation.