Finding, and losing, Majorana

I’m looking forward to breaking down and understanding a new paper in Physical Review B soon – the sort of work of condensed-matter physics that’s complex enough to warrant a week-long dive into the subject but not so complex as to leave a non-expert enthusiast (such as myself) eventually stranded in a swamp of mathematical intricacies. But while I’m going to do that, I thought I should also make a note of how differently the paper’s principal interestingness has been presented by its publisher and by its authors. The American Physical Society, which publishes Physical Review B, tweeted this on June 21:

On the same day, both Microsoft (where the paper’s authors are employed as researchers) and a slew of popular science outlets, including Popular Science (which doesn’t once say “Majorana”), published articles claiming the tech company had achieved, in its own words, the “first milestone towards a quantum supercomputer”.

The existence of Majorana zero modes do lead to the possibility of a quantum computer that uses topological qubits as its basic information-bearing units (like the semiconductors of a classical computer). But we don’t even have a quantum computer yet, yet here we have reports about a quantum supercomputer well in the future. I understand that quantum computing is regularly in the news now, that Microsoft itself is calling the new study a step towards a supercomputing version of such a device, and that doing so is a sure-shot way to draw public attention towards the work.

But something about looking away from the past, from the long quest for observing these states in different intricately engineered systems, in order to focus on the future sits ill with me. That physicists have finally found a way that could work should be the headline, if only to hang on to the idea that Majorana modes are valuable in more ways than to build a quantum supercomputer, as well as to commemorate – in a manner of speaking – what physicists of the past did and didn’t get right, especially when they didn’t have the tools and the knowledge that they do today.

It also matters that a private technology company is undertaking this research. The Microsoft researchers published their results as a scientific paper, but what’s to say a different private entity won’t uncover some important bit of physics, not publish any papers about it, proceed straight to applying it in some lucrative technology, and keep their findings under wraps? I imagine that, on some epistemic spectrum, knowledge of the natural universe seamlessly transforms at some point into the know-how of building a highly profitable (or highly destructible, for that matter) machine. Yet some knowledge of the former variety belongs with the people at large, even if the knowledge of the latter kind need not.

Part of the issue here is that the study of topological phases of matter has progressed almost in step with, and oftentimes been motivated by challenges in, efforts to build a better quantum computer. This is a good thing – for privately employed researchers to advance science, even if in the pursuit of profit – but that resulting scientific knowledge eventually has to be out, and made available as part of the public commons. Microsoft did that (by publishing an open-access paper in Physical Review B); I’m disappointed that some of the science journalists who took over at that point, in efforts to take that knowledge to the people at large, fell short.