How capable are today’s quantum computers?

Episode Summary

Executive Summary: The episode explores the state of quantum computing through the lens of Quantum 2020 and Google’s current research. It highlights the field’s shift from theory to application, the rise of noisy intermediate-scale quantum devices, the importance of materials science and cryogenics, and how global collaboration, industry, and academia are converging around real-world quantum technologies.

Main Topics: Quantum 2020 conference and global collaboration: Tim Smith explains how the originally planned Beijing in-person event became a free virtual conference, designed to connect international quantum communities and bridge academia with industry. Quantum computing progress at Google: Ryan Bubish describes the current state of quantum hardware, emphasizing that today’s machines can run beyond-classical simulations but remain noisy and not yet error-corrected. Noisy intermediate-scale quantum (NISC) devices: The discussion distinguishes present-day quantum processors from the long-term goal of fully error-corrected quantum computers, noting the prevalence and impact of operational errors. Materials science as a bottleneck and enabler: Both speakers stress that scaling quantum technologies depends heavily on advances in materials science, fabrication quality, and qubit design. Cloud access and near-term quantum applications: Google’s approach is framed around cloud-based access to quantum devices, with current use cases centered on chemistry, material science, and high-performance computing rather than home use. Community-building, publishing, and early-career recognition: IOP Publishing uses the event to promote journals, peer review discussion, and two new awards recognizing early-career scientists in quantum science and technology.

Key Arguments: Quantum science has moved from a mostly theoretical subject to a field with clear commercial and technological potential. The pandemic forced Quantum 2020 to shift online, but that change expanded accessibility and made the event free to attend. Current quantum processors are already powerful enough to perform tasks that cannot be classically simulated, even though they are still error-prone. Error correction remains the central long-term challenge before fully reliable quantum computers can be built. Materials science is essential for scaling qubits and turning quantum devices into practical technologies. Quantum computers are more likely to be accessed through the cloud in the near term than to appear as consumer home devices. The field is increasingly collaborative and international, with national programs seeking both competition and cooperation. Quantum computing may eventually help accelerate its own development by improving material science and fabrication methods.

Data Points: Conference dates: 19th to 22nd of October - Quantum 2020 schedule Number of national programs on panel: 8 - Panel on global quantum technology programs Countries/programs named on panel: China, UK, Canada, Australia, Japan, US, EU quantum flagship - Examples of represented national initiatives Delegates registered: Several thousand - Quantum 2020 attendance at time of interview Countries represented: 92 - International sign-up for Quantum 2020 PhD age for early-career award: Within 3 years - One of the new IOP Publishing awards PhD age for second award: Within 8 years - Second IOP Publishing award for outstanding achievement Operating temperature: 15 millikelvin - Approximate temperature of Google’s superconducting qubit devices Error frequency: 50% to 90% - Ryan Bubish describes error rates in larger circuits on noisy devices Quantum system scale: Million-run repetitions - Same circuit may be run a million times to estimate correct outcomes

Pivotal Quotes: "we have devices now which are large enough that they can execute quantum programs that you can't simulate classically" — Ryan Bubish: Explaining the capability of current quantum hardware "the challenge of scalability and material science in the creation of qubits ... has a major role to play" — Tim Smith: Discussing why materials science matters for quantum technology "they're usually hanging upside down from the ceiling and have, you know, tens or hundreds of thousands of wires coming out of them" — Ryan Bubish: Describing the physical appearance of today’s superconducting quantum computers

Implications: Quantum computing is moving toward practical use, but progress depends on solving noise, scaling, and materials challenges. For listeners and industry, the near-term future is cloud access, cross-sector collaboration, and faster development driven by international research communities.