Magnetism and Superconductivity: An Unexpected Alliance express
Using laser spectroscopy — a method akin to listening to the echo from a crystal — physicists examined the layered material. They found regions where electrons move freely (Fermi pockets) and noticed that each such region behaves in its own way.
Previously, magnetic order — where electron spins line up in a strict row — was considered an enemy of superconductivity, making it hard for electrons to pair up. But here, the two not only coexist: superconductivity blossoms right inside the magnetized zone. Magnetism doesn't hinder but rather seems to accompany the paired dance of electrons, like a stern teacher who suddenly begins to play along with a student duet.
Upon transitioning to the superconducting state, the system's entropy (a measure of disorder) drops sharply — order increases. And here's an unexpected twist: in one layer, the energy gap (the threshold to break a pair) reached 42 meV — anomalously high for such a material. This discovery overturns theories developed by Bardeen and Landau, showing that the standard model is too simplistic to describe high-temperature superconductivity. The practical goal: lossless wires.
The material is a cuprate — the first type of superconductor to work with liquid nitrogen cooling (–196°C). Their discovery in 1986 caused a sensation comparable to the space race, spawning an avalanche of documentaries.
In science fiction, superconductors are the key to levitating trains and eternal energy. The discovery of their alliance with magnetism makes these dreams a bit more real.