Impurity-induced excitations in twisted topological van der Waals superconductors

Abstract

Twisted van der Waals materials have provided a new platform realizing artificial topological superconductivity, as demonstrated in twisted CrBr3/NbSe2 heterostructures. The emergence of a topological superconducting state in a twisted van der Waals material provides a new platform for exploring new strategies to control topological superconductors, potentially exploiting unique features associated with a moire pattern. In particular, impurities in moire superconductors can potentially lead to the unique interplay between atomic and moire length scales, a feature absent in generic topological superconductors. Here we address the impact of non-magnetic impurities on a topological moire superconductor, both in the weak and strong regime, considering both periodic arrays and single impurities in otherwise pristine infinite moire systems. We demonstrate a fine interplay between impurity induced modes and the moire length, leading to radically different spectral and topological properties depending on the relative impurity location and moire lengths. Our results highlight the key role of impurities in topological moire superconductors, revealing the key interplay between length and energies scales in artificial moire systems.

Ferroelectric valley valves with graphene/MoTe2 van der Waals heterostructures

“…4g) the interface modes show a modulation in real space following the moiré potential. 27,60 It is worth noting that such a moire modulation does not lead to intervalley scattering, as demonstrated by the gapless nature of the spectral function of Fig. 4d.…”

Effects of electron-electron interactions in the Yu-Shiba-Rusinov lattice model

“…The case of a two-dimensional Yu-Shiba-Rusinov lattice is theoretically even more interesting [12,[28][29][30][31][32][33][34][35][36]. In this case the hybridization of the Yu-Shiba-Rusinov states gives rise a rich phase diagram containing large number of different topological phases [12,[30][31][32].…”