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 …

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 flat band superconductor, bosonic excitations can disperse while unpaired electrons are
immobile. To study this strongly interacting system, we construct a family of multi-band …

The importance of the quantum metric in flat-band systems has been noticed recently in
many contexts such as the superfluid stiffness, the dc electrical conductivity, and ideal Chern …

Bloch wave functions of electrons have properties called quantum geometry, which has
recently attracted much attention as the origin of intriguing physical phenomena. In this …

In the pursuit of higher critical temperature of superconductivity, quasiflat electronic bands
and Van Hove singularities in two dimensions (2D) have emerged as a potential approach …

The coherence length ξ is the fundamental length scale of superconductors which governs
the sizes of Cooper pairs, vortices, Andreev bound states, and more. In BCS theory, the …

We review the theoretical description of the role of quantum geometry in superfluidity and
superconductivity of multiband systems, with focus on flat bands where quantum geometry is …

Anapole superconductivity recently proposed for multiband superconductors [S. Kanasugi
and Y. Yanase, Commun. Phys. 5, 39 (2022) 2399-3650 10.1038/s42005-022-00804-7] is a …

Noncentrosymmetric superconductors offer fascinating phenomena of quantum transport
and optics such as nonreciprocal and nonlinear responses. Time-reversal symmetry …