Higher order topological defects in a moiré lattice

Eugenio Gambari (1) , Sebastian Meyer (2, 3) , Sacha Guesne (1) , Pascal David (1) , François Debontridder (1) , Laurent Limot (4) , Fabrice Scheurer (4) , Christophe Brun (1) , Bertrand Dupé (5, 6) , Tristan Cren (1) , Marie Hervé (1)

1 INSP - Institut des Nanosciences de Paris
2 Université de Liège, Nanomat/Q-mat/CESAM
3 Fonds de la Recherche Scientifique [FNRS]
4 IPCMS - Institut de Physique et Chimie des Matériaux de Strasbourg
5 Université de Liège
6 FNRS - Fonds National de la Recherche Scientifique [Bruxelles]

Topological defects are ubiquitous, they manifest in a wide variety of systems such as liquid crystals, magnets or superconductors. The recent quest for nonabelian anyons in condensed matter physics stimulates the interest for topological defects since they can be hosted in vortices in quantum magnets or topological superconductors. In addition to these vortex defects, in this study we propose to investigate edge dislocations in 2D magnets as new building blocks for topological physics since they can be described as vortices in the structural phase field. Here we demonstrate the existence of higher order topological dislocations within the higher order moir´e pattern of the van der Waals 2D magnet CrCl3 deposited on Au(111). Surprizingly, these higher order dislocations arise from ordinary simple edge dislocations in the atomic lattice of CrCl3. We provide a theoretical framework explaining the higher order dislocations as vortex with a winding Chern number of 2. We expect that these original defects could stabilize some anyons either in a 2D quantum magnet or within a 2D superconductor coupled to it.

Mots clés: Moiré pattern; Topological defects; Van der Waals materials; Scanning Tunneling microscopy; Scanning Tuneling Spectroscopy; Density functional theory; Transition metal surfaces

Domaines: Physique [physics]

Eugenio Gambari, Sebastian Meyer, Sacha Guesne, Pascal David, François Debontridder, et al.. Higher order topological defects in a moiré lattice. 2024. ⟨hal-04544986⟩