Toward cloud-based quantum computing

Universal quantum computers with thousands of logical quantum bits are still largely theoretical. At present, most quantum computer prototypes involve less than 10 individually controllable qubits, and exist only in laboratories due to high costs and unusual maintenance requirements. Some scientists believe that quantum computers will never replace classical computers, but would instead serve as a supplement when tackling particular problems. Thus, cloud-based quantum computing is anticipated as a likely solution.

As initial attempts, IBM Q has launched cloud services on a superconducting quantum processor in 2016, but no other cloud services have followed up yet in china. Recently, three research teams launched their cloud services on the same day. A joint team led by G. Long at Tsinghua University, B. Zeng at University of Guelph and D. Lu at SUSTech presented NMRCloudQ, which is based on nuclear magnetic resonance. NMRCloudQ provides a comprehensive software environment and aims to be freely accessible to either amateurs that look forward to keeping pace with this quantum era or professionals that are interested in carrying out real quantum computing experiments in person.

In the current version, NMRCloudQ provides users with 20 single-qubit gates and 9 two-qubit gates for building a quantum circuit online, and a density matrix of the final state after completing experiments. Randomized benchmarking tests show that average 99.1 percent single-qubit gate fidelity and 97.15 percent two-qubit fidelity were achieved. Soon, the service will provide improved control precisions after updating a new sample with longer coherence time and stronger coupling between different nuclei. Benefitting from the mature techniques in experimental quantum computing, NMRCloudQ may open the control layer to users in the future.

More information:
Tao Xin et al, NMRCloudQ: a quantum cloud experience on a nuclear magnetic resonance quantum computer, Science Bulletin (2017). DOI: 10.1016/j.scib.2017.12.022

Provided by Science China Press