Existence of crystallographic-invariant exponentially localized Wannier functions in topological insulators

par Marco Valerio D'Agostino (INSA Lyon)

vendredi 4 oct. 2024, 14:00 → 15:00 Europe/Paris

salle 112 (Bâtiment Braconnier)

The problem of investigating the presence of topological obstructions to the existence of crystallographic invariant exponentially localized Wannier functions in topological insulators is addressed. When crystallographic groups are considered, twists in ordinary K-theory must be taken into account. The case of the Haldane model is used to demonstrate how an explicit algorithmic procedure can be set up to effectively construct invariant exponentially localized Wannier functions whenever no topological obstructions are present.