Room Temperature Superconductivity - Sufficiently Advanced - By Luke Richardson

Scientists have done it - the decades long search for a room temperature superconductor (RTS) is over. Carbonaceous sulphur hydride is the name of the new wonder-material, but it has a few problems. Unfortunately, it only works at pressures approaching those found in the Earth’s core, and even then at room temperatures that could be called “parky”. You might wonder, what is the point of making such a fundamentally useless material? Apart from chasing records and acclaim, how does this help anybody in the search for the holy grail of materials science?

It’s always good to remember why people care so much about room-temperature superconductors. These materials have the potential to revolutionise our technology, and their impacts could be so far reaching that it is almost impossible to overstate. A good room-temperature superconductor could replace batteries, as if you put some current in a loop of superconducting wire it will go round and round forever. A superconducting

battery could hold charge indefinitely as long as it doesn’t get too hot, and wouldn’t degrade over time like lithium ion cells do. The devices powered by these batteries wouldn’t get nearly as hot, as there would be no resistance to produce heat. Explaining the advantages of RTSs can be tricky because resistance is such a fundamental limitation of our technology that everyone works around it almost instinctively. The question is a bit like asking how cars would be different if they didn’t have to worry about friction with the air. You could build the Homermobile and still end up with an efficient car. RTSs would be nothing less than the death of a fundamental limitation on our technology.

If that wasn’t enough, RTSs could also make all of the superconducting tech we already have much cheaper. MRI machines depend on superconductors, but current ones must be kept far below freezing by being immersed in liquid gas, in complex and expensive cryogenic cooling systems known as cryostats. Being able to do away with cryostats will make MRIs smaller, and a lot cheaper. US military studies have shown that immediately scanning people with traumatic injuries drastically increases their chances of survival. In a superconducting future, everyone taken to an A&E could be scanned immediately, removing guesswork and providing life-saving certainty to doctors and patients alike. Superconductors can famously levitate., a property applied in maglev trains, already the fastest trains on Earth. These also have to lug around cryostats and coolant, and RTS will make these trains much simpler, hopefully to the point where they can be applied to subways and regional lines. The same goes for supercolliders- not having to bother with cryostats will vastly simplify things. The LHC at CERN cost £3.7 billion, a handsome proportion going to the vast liquid helium cryostats that are needed to cool the ring. Some more exotic proposals could produce vast dark matter detectors, and magnetic detectors sensitive enough to find a submarine under a kilometre of ice.

Do you want an office chair that levitates? RTSs can do it! Batteries that never drain, lossless undersea power transmission between continents, much smaller and more powerful motors, smaller faster processors, the ability to levitate stuff if you really want, permanent magnets stronger than Neodymium, lossless regenerative braking, cheap cameras that can record a single photon and beaming power to and from space are all up for grabs. Detectors sensitive enough to measure the magnetism of a single atom, devices that could be stored idle with a full charge forever, detectors of exotic particles small enough to carry. The applications border on the territory of devices that Arthur C. Clarke might’ve called “Sufficiently advanced to be indistinguishable from magic”.

So, coming back to the latest discovery. This new RTS is not going to find use in anything, as it can only exist in the extreme conditions of a diamond anvil cell. However, it is an impressive validation of the theory that underpins superconductivity, Bardeen–Cooper–Schrieffer or BCS theory. Once the team achieved superconductivity, they tested a prediction of BCS; namely that applying a very strong magnetic field will disrupt the ability of the material to be a superconductor. The breakdown in superconductivity occurred at the strengths predicted by BCS modelling. While the study didn’t produce a reel of ready-to-go superconducting wire, it is an impressive validation of the best theory we have for understanding how superconductivity works. Understanding how BCS theory applies to materials science will be essential for one day achieving room temperature AND pressure superconductors. If you have this stuff, the possibilities are endless.

P.S. We’d better start calling the wonder-material a room temperature and pressure superconductor, so scientists can’t sneak through on a technicality again. RTPS!