Two RIKEN physicists have established new theoretical limits for experimentally measurable quantities by viewing solids through a lens of quantum geometry. Their results shed light both on the physics of solids and on quantum mechanics.

The usual approach to studying a solid in physics is to consider all the interactions acting between its atoms or molecules and then use the laws of quantum mechanics to determine the solid’s properties. But a new methodology involves considering the “quantum geometry” of a solid. It entails studying the geometric structures that arise not in physical space, but in the space of quantum states.

One of the key concepts in this approach is the quantum geometric tensor—a matrix that contains information about the distances and curvatures of quantum states.