You have definitely heard of electronics. You may (if you are a tech nerd like me) have heard of spintronics and photonics. Now there is also the possibility of orbitronics. What do these cool-sounding words mean?

Electronic technology is one of those core technologies that has transformed our civilization. Prior to harnessing electricity and developing electrical engineering we essentially had steam punk – mechanical, steam-powered technology. Electronics and electricity to power them, however, opened the door to countless gadgets, from electric lights, appliances, handheld devices, and eventually computer technology and the internet. I am occasionally reminded of how absolutely essential electricity is to my daily life during power outages. I get a brief glimpse of a pre-electronic world and – well, it’s rough. And that’s just a taste, with the real drudgery prolonged life without power would require.

Increasingly electronic devices are computerized, with embedded chips, possibly leading to the “internet of things”. Data centers eat an increasing percentage of our power production, and the latest AI applications will likely dramatically increase that percentage. Power use is now a limiting factor for such technology. It’s one main argument against widespread use of cryptocurrencies, for example. To illustrate the situation, Microsoft has just cut a deal to reopen Unit 1 at the Three-Mile Island nuclear power plant (not the one that melted down, that was Unit 2) with an agreement to purchase all of its power output for 20 years – to power its AI data center.

Therefore there is a lot of research into developing computer hardware that is not necessarily faster, smaller, or more powerful but is simply more energy efficient. We are getting to the limits of physics with the energy efficiency of electronic computers, however. Software engineers are also focusing on this issue, trying to create more energy-efficient algorithms. But it would be nice if the hardware itself used less energy. This is one of the big hopes for developing high temperature superconductors, but we have no idea how long or if we will develop anything usable in computing.

The other options is to fundamentally change the way computers work, to rely on different physics. Electronic computers transfer information essentially in the electrical charge of an electron (I say “essentially” to deliberately gloss over a lot of details that are not necessary to discuss the current news item). The current leading contender to replace (or supplement) electronic is photonics, which uses light instead of electrons to transfer information. Photonics are more energy efficient, generate less waste heat, have less data loss, and use smaller devices. Photonic integrated circuits are already being used in some data centers. Photonic computers were first proposed in the 1960s, so they have been a long time coming.

There are also other possible physical phenomenon that could be the basis of computing in the future. The basic science is just being worked out, which to me means that it will likely be a couple of decades, at least, before we see actual applications. One option is spintronics, which uses the spin of electrons, rather than their charge, in order to carry information. Spintronics is also faster and more energy efficient than electronics. Spintronic devices could also store information without power. But they have technological challenges as well, such as controlling spin over long distances. It’s likely that spintronic and photonic devices will coexist, depending on the application, and may even be integrated together in opto-spintronics.

Enter orbitronics – another possibility that uses the orbital angular momentum (OAM) of electrons as they orbit their nucleus as a way of storing and transferring information. The challenge has been to find materials that allow for the flow of OAM. OAM has the advantage of being isotropic – the same in every direction – so it can potentially flow in any direction. But we need a material where this can happen, and we need to control the flow. That material was possibly discovered in 2019 – chiral topological semi-metals, or chiral crystals. Chiral means that they have a handedness, in this case a helical structure like DNA. But in order to work it would need OAM monopoles, which are only theoretical. That is where the new study comes in.

Researchers have demonstrated that OAM monopoles actually exist. They also showed that the direction of the monopole can be flipped – from pointing out to pointing in, for example. These are properties that can be exploited in an orbitronics-based computer technology. The article, which is available at Nature, has the details for those who want to get into the technical weeds.

As always, it’s difficult to predict how potential new technologies will pan out. But we can make optimistic predictions – if everything works out, here is a likely timeline. We are on the cusp of photonics taking off, with projected significant growth over the next decade. This will likely be focused in data centers and high-end consumer devices, but will trickle down over time as the technology becomes more affordable. Photonics, in other words, is already happening. Next up will likely be spintronics, which as I said will most likely complement rather than replace photonics.

Orbitronics, if it pans out, and has sufficient advantages over photonics and spintronics, is likely more a technology for the 2040s, or perhaps 2050s. There is also the possibility that some other new technology will eclipse orbitronics (or even spintronics) before they can even get going.