Scale-invariant magnetoresistance in a cuprate superconductor

Cranking up the field Cuprate superconductors have many unusual properties even in the “normal” (nonsuperconducting) regions of their phase diagram. In the so-called “strange metal” phase, these materials have resistivity that scales linearly with temperature, in contrast to the usual quadratic dependence of ordinary metals. Giraldo-Gallo et al. now find that at very high magnetic fields—up to 80 tesla—the resistivity of the thin films of a lanthanum-based cuprate scales linearly with magnetic field as well, again in contrast to the expected quadratic law. This dual linear dependence presents a challenge for theories of the normal state of the cuprates. Science , this issue p. 479