CM In the literature: contested

Superconducting gap structure of AV3Sb5

In plain words

Whether the superconducting gap of these kagome metals vanishes somewhere on the Fermi surface, and whether it changes sign, is disputed.

Precise statement

Determine the gap structure of AV3Sb5 superconductors (nodal or nodeless, sign-changing or not) and its dependence on the charge-density-wave state, for example under pressure where $T_{c}$ has two domes. An answer is penetration depth, thermal conductivity and phase-sensitive measurements on the same crystals, with controlled disorder to test sign change.

What would settle it

Penetration depth with electron-irradiation series and thermal conductivity, plus quasiparticle interference sign tests.

Status in the literature

Penetration depth with controlled electron irradiation (2023) points to a nodeless sign-preserving gap; other reports infer nodes.

See also