The superfluid weight measures how readily a superconductor carries supercurrent; it sets the magnetic penetration depth and can limit the critical temperature, which makes it a useful descriptor in computational searches for new superconductors. Researchers in QMAT's Quantum Dynamics group at Aalto University and colleagues have developed an efficient way to calculate it from density functional theory band structures and wavefunctions.

The framework separates the conventional contribution from band curvature and the geometric contribution from quantum geometry. Penetration depths calculated for Al, Pb, Nb, MgB₂, LuRu₃B₂ and YRu₃B₂ agree well with experiment after corrections. The authors include Kaja Hiorth, Martin Gutierrez-Amigo and Päivi Törmä at Aalto, with partners at Ruhr University Bochum and Rutgers University.

Image: QMAT