Superconductivity has been observed in moiré systems such as twisted bilayer graphene,
which host flat, dispersionless electronic bands. In parallel, theory work has discovered that …

Certain lattice wave systems in translationally invariant settings have one or more spectral
bands that are strictly flat or independent of momentum in the tight binding approximation …

A central result in superconductivity is that flat bands, though dispersionless, can still host a
nonzero superfluid weight due to quantum geometry. We show that the derivation of the …

In a series of recent reports, doped lead apatite (LK-99) has been proposed as a candidate
ambient temperature and pressure superconductor. However, from both an experimental …

While regular flat bands are good for enhancing the density of states and hence the gap,
they are detrimental to the superfluid weight. We show that the predicted nontrivial topology …

We study superconductivity of twisted bilayer graphene with local and nonlocal attractive
interactions. We obtain the superfluid weight and Berezinskii-Kosterlitz-Thouless (BKT) …

In flat bands, superconductivity can lead to surprising transport effects. The superfluid
“mobility”, in the form of the superfluid weight D s, does not draw from the curvature of the …

We present a theory of the superfluid weight in multiband attractive Hubbard models within
the Bardeen-Cooper-Schrieffer (BCS) mean-field framework. We show how to separate the …

We show that flat bands can be categorized into two distinct classes, that is, singular and
nonsingular flat bands, by exploiting the singular behavior of their Bloch wave functions in …

We introduce the concept of “quantum geometric nesting”(QGN) to characterize the
idealized ordering tendencies of certain flat-band systems implicit in the geometric structure …