What happens if you take two sheets of graphene and rotate one slightly relative to the other?” It’s a question all of us must have asked ourselves at one point or another (it is?-ed) but never really found time to answer. But two remarkably intelligent men did: Allan MacDonald, a theoretical physicist who posed it; and Pablo Jarillo‑Herrero who answered it by building ultra‑clean, precisely controlled graphene heterostructures –you know: the kind of devices where quantum subtleties become visible. Well, we said they were clever! Their work, and the prize which they won for it are admirably summarised by the erudite Selva Vargas Reátegui for El País [1]
Her excellent article contains much more on the details, so read it. Suffice it to say, the discovery not only revealed all sorts of weird and wonderful properties in graphene. It actually created a whole new field of learning: Twistronics. Because researchers soon learned to twist not just bilayers as in graphene, but trilayers, multilayers, and heterostructures of many 2D materials. The field exploded because twist angle becomes a new starting point for designing quantum matter. While still early, the work hints at possibilities such as: designer superconductors, quantum simulation platforms, ultra‑sensitive sensors and novel electronic devices based on correlated phases. Ok we are a tad shaky on one or two of these ourselves, but if it helps build something to do the ironing, we’re all in.
But the real point for us is conceptual. Changing the geometry alone can utterly change the properties of a material. It feels a bit like the time when some unknown genius in Old Mesopotamia started mixing tin with copper. As small, as unexpected and as potentially world changing. Oh, and another point: economics. The more you spend on basic science and research, the more your chances rise of repeating the trick somewhere else. Leaders of the world, you have nothing to lose but your accountants.
Premio Fronteras para los descubridores del ‘ángulo mágico’ que genera supermateriales | Ciencia | EL PAÍS English speakers: you need to hit the translation button
#Twistronics #graphene #quantum physics #geometry #bronze age #materials science
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