I wanted to mention something on the border between chemistry and physics that might well turn out to be important. Graphene (single-layer graphite, a two-dimensional carbon sheet of fused aromatic rings) has been a hot topic for some years, but this will make it a hotter one. It is an absolute requirement that every time you write about graphene that you mention that the breakthrough in its isolation came from the use of adhesive tape, a low-tech insight at Manchester that led to a Nobel and kicked off a massive field of research. The latest is that earlier this month, a group at MIT reported that if you bring two graphene sheets together, parallel but at a slightly different rotational angle (about 1.1 degrees), that the system becomes a superconductor at low temperatures.

That was already unexpected, but the behavior of the material (electron density versus temperature) suggests some real similarities to the copper-oxide high-temperature superconductors, and no one saw that coming, either. (Note that “high temperature”, in this field, still means “can be reached in liquid nitrogen as opposed to liquid helium”). Despite a really impressive amount of theoretical and experimental work on the cuprate materials, the full details of their superconductivity are still a matter of debate. It seems to come down to Cooper pairs (as with the classic low-temperature superconductors, but the mechanism of the electron pairing is different and in ways that still start arguments. This new graphene systems might be able to shed some light on the various proposals, and you can be certain that a great deal of late-night coffee has been consumed in recent weeks to come up with appropriate experiments along these lines.

The practical value of such an understanding could well be huge (and there is, of course, another near-certain Nobel in physics waiting for whoever puts the field on a firmer basis). To give another recent MIT-related example, new superconductor engineering is at the heart of a recent announcement the university made about fusion power. The belief is that large-bore magnets of such materials, which now appear feasible, could allow a tokamak-design fusion reactor that is far more compact than any previous attempts. Wrestling with the magnets is one of the biggest problems in designing such machines, because you need extremely strong, extremely homogeneous fields. The high-temperature superconductors were recognized early on as having great possibilities in this area, but the first fusion reactor that used only these materials only became operational in 2014 (a spherical tokamak design at Tokamak Energy in the UK).

The graphene-layer materials are still operating at very low temperatures – but considering their electron density, it’s actually a lot higher than it should be. No one is going to be make fusion reactors with twisted-graphite magnets any time soon, but twisted graphite might possibly be the platform that leads us to the magnets that fusion reactors will use.