The original version from This story appeared in Quanta Magazinee.
In 2024, superconductivity—electrical flow with zero resistance—was discovered in three separate materials. Two cases extend the textbook understanding of the phenomenon. The third crushes it completely. “This is an incredibly unusual form of superconductivity that many people say is not possible,” says Harvard University physicist Ashwin Vishwanath, who was not involved in the discovery.
Superconductivity has fascinated physicists since 1911, when Dutch scientist Heike Kamerling Onnes first observed the disappearance of electrical resistance. There is a pure mystery as to how it happens: the phenomenon requires electrons that carry electric current to pair up. Electrons repel each other, so how can they be united?
Then there’s the promise of technology: already, superconductivity has enabled the development of powerful MRI machines and particle colliders. If physicists could fully understand how and when this phenomenon occurs, they might be able to engineer a wire that conducts electricity in everyday conditions rather than exclusively at low temperatures. World-changing technologies—lossless power grids, magnetically propelled vehicles—may follow.
The wave of recent discoveries has both intensified the mystery of superconductivity and increased optimism. “Superconductivity seems to be everywhere in materials,” says Matthew Jankowitz, a physicist at the University of Washington.
The discoveries stem from a recent revolution in materials science: All three new examples of superconductivity arise in devices assembled from flat sheets of atoms. These materials show unprecedented flexibility. At the touch of a button, physicists can switch them between conducting, insulating, and more exotic behaviors—a modern form of alchemy that has greatly increased the hunt for superconductivity.
Now it seems increasingly likely that various causes can lead to this phenomenon. As birds, bees, and dragonflies fly with different wing structures, materials appear to pair electrons in different ways. Even as researchers debate exactly what’s going on in the various two-dimensional materials in question, they predict that the growing zoo of superconductors will help them gain a more global view of the fascinating phenomenon. find
Pairing of electrons
The observation of Kamerlingh Onnes (and superconductivity seen in other very cold metals) was finally broken in 1957. John Bardeen, Leon Cooper, and John Robert Schrifer discovered that at low temperatures, the unstable atomic lattice of a material is quenched, so most subtle effects through. The electrons gently pull the protons in the lattice, pulling them inward to create an additional positive charge. That change, known as a phonon, can pull a second electron in, forming a “Kooper pair.” Cooper pairs can all come together into a coherent quantum entity, in a way that a single election cannot. The resulting quantum soup slides between atoms of matter without friction, which would normally disrupt electrical current.
Bardeen, Cooper, and Schriefer won the Nobel Prize in Physics in 1972 for phonon-based superconductivity. But it turned out that was not the whole story. In the 1980s, physicists discovered that copper-filled crystals called cuprates could become superconducting at higher temperatures, where atomic vibrations annihilate phonons. Other similar examples followed.
