Under pressure, the layered crystal La₃Ni₂O₇ behaves like an orchestra where the conductor adjusts the volume of different instrument sections. Compression increases electron hopping between layers — which, one might think, should boost superconductivity. But at the same time, some electrons become too mobile.

The main intrigue lies in two types of nickel orbitals. Electrons in dx²-y² increasingly resemble free travelers, while their neighbors in dz² stay homebodies. When travelers become numerous, they start to screen the magnetic moments of the homebodies — an effect similar to Kondo screening (a phenomenon where a cloud of free electrons quenches the magnetic field of an impurity). The magnetic interaction that served as the glue for electron pairs weakens.

This is how the dome on the phase diagram is born: superconductivity first strengthens, then is extinguished by the very pressure that created it. The orbital duo regulates its own fate, like an orchestra where the solo section unexpectedly drowns out the rest.