How to Make Gold a Superconductor ⚡ экспресс
The study found that superconductivity can emerge in ultra-thin films (less than a nanometer thick) of metals that aren’t normally superconducting—like copper, silver, gold, and alkali or alkaline earth metals. Using the generalized Eliashberg theory, researchers calculated the critical temperature as a function of thickness: it only shows up in narrow windows (0.4–0.6 nm) and only for certain elements—it's like finding a needle in a haystack. In layered hybrid structures, the proximity effect can significantly boost the transition temperature.
In a thick metal, electrons are like a discordant orchestra: each instrument plays on its own, the overall sound is noise. But roll the metal into a film just a couple of atoms thick—and electrons suddenly begin to "play" in harmony, conducting current without dissonance. Even John Bardeen explained that in superconductors, electrons form pairs—duets that move unimpeded. Now, armed with an updated model and spectroscopy, scientists have calculated that this "concert" is only possible at a thickness of 0.4–0.6 nm. Any thicker, and disorder returns: the duets break apart, cacophony ensues. Cooling such an "orchestra" requires liquid helium—down to ultra-low temperatures.
Interestingly, if you place a layer of ordinary metal on top of such a film, the critical temperature rises—as if the music got louder in a good concert hall. This is the proximity effect.
🎯 The first predictions of superconductivity in thin films appeared back in the 1960s, but only modern computational methods have made it possible to accurately estimate the necessary thicknesses.