How capable are today’s quantum computers?

Media coverage of quantum computing often focuses on the long term potential for these devices to leave classical computing in the dust. But what about the rudimentary quantum systems that are already being developed and tested by technology companies? What are the latest advances in the field? And what might these systems realistically be able to achieve in the short to medium term? Andrew Glester investigates these questions in the latest episode of the Physics World Stories podcast.

The episode previews Quantum 2020, a free online event running 19–22 October hosted by IOP Publishing (which also published Physics World). Tim Smith, associate director for journals product development, describes how the conference will cover the latest developments across quantum science and technology. While Claire Webber, associate director for content and engagement marketing, explains how you can participate in the event.

Glester then catches up with one of the speakers at Quantum 2020 – Ryan Babbush, head of quantum algorithms at Google. In 2019 Google made headlines after asserting that its Sycamore quantum processor was the first to achieve “quantum supremacy”, whereby a quantum computer solves a problem in a significantly shorter time than a conventional computer. Although the specifics of that claim have been disputed, it was still celebrated as a key breakthrough in the field.

Babbush describes some of the key goals for Google’s first generation of practical quantum computers. One of them is to realize Richard Feynman’s idea of using quantum devices to simulate physical systems that behave according to the laws of quantum physics. Such a system could be used to solve the fiendishly complex chemistry equations required to predict the properties of new materials. Another key goal is quantum cryptography, which could offer secure communication systems.