Articles in the popular press have given competing experimentalists the opportunity for some polite scientific knocking copy

A series of recent articles across the New Scientist, Financial Times and Bloomberg quote leading experimental groups, and give insight into the state of reality and hype in the nascent quantum computing sector. Different scientific groups have spent years developing alternative technologies for the qubits upon which they plan to build useable quantum computers. Many of these groups now have corporate backing. The competition is on, but remains polite.

The superconducting qubits crowd talks up the importance of demonstrating quantum supremacy, completing a (carefully chosen) calculation unfeasible on any conventional computer. This will be a genuine milestone, and one they seem best placed to achieve. By coincidence, rival corporate teams have been conducting research to raise the bar by improving conventional supercomputer algorithms.

The trapped ion guys boast of their high quality qubits, cough, and talk under their breath about all the messy cryogenics others need and how difficult that will be to scale up to truly large machines.

The silicon based Aussies say g’day to a core technology that is the only one the existing microelectronics industry actual has experience with scaling up.

On top of these physical qubits the surface code wizards intone about easy 2D encoding of logical qubits, but stay silent on their voracious hunger for magic states.

The most poetic quote comes in the New Scientist from the topological qubit underground “There are people running the marathon already, but they’re wearing army boots. We’re still sitting there putting on our running shoes”. When your technology relies on working with braided non-abelian anyons realised as Majorana quasiparticles on the end of nanowires, then it’s probably right that you spend time finding simple ways to explain the point to the business community.

The competing technologies will likely continue to evolve in parallel for some time. In the end we may well see not just one winning platform but specialised niche applications for quantum memory, quantum repeaters, specialist co-processors, sensors, quantum simulators and more. Proponents of photonic approaches would certainly emphasise their natural affinity with optical networks and distributed approaches. NV diamond groups would point to their robust physical nature and easy compatibility with sensing applications.

Interestingly none of the physicists quoted in these recent articles seem to have insisted that it’s meaningless to speculate on the physical reality of their qubit technologies, and that only macroscopic processes of measurement should be considered meaningful. But I suppose real investors were never going to buy that sort of mumbo jumbo. It seems that the Copenhagen interpretation of quantum mechanics has collapsed upon first observation by venture capital.

Many thanks to Michael Brooks (New Scientist), Robin Wigglesworth & Richard Waters (Financial Times) and Jeremy Kahn (Bloomberg) for their great press articles.