Jesper R Moes, Jara F Vliem, Pedro M M C de Melo, Thomas C Wigmans, Andrés R Botello-Méndez, Rafael G Mendes, Ella F van Brenk, Ingmar Swart, Lucas Maisel Licerán, Henk T C Stoof, Christophe Delerue, Zeila Zanolli, Daniel Vanmaekelbergh
The remarkable development of colloidal nanocrystals with controlled dimensions and surface chemistry has resulted in vast optoelectronic applications. But can they also form a platform for quantum materials, in which electronic coherence is key? Here, we use colloidal, two-dimensional Bi2 Se3 crystals, with precise and uniform thickness and finite lateral dimensions in the 100 nm range, to study the evolution of a topological insulator from three to two dimensions. For a thickness of 4-6 quintuple layers, scanning tunneling spectroscopy shows an 8 nm wide, nonscattering state encircling the platelet...
April 16, 2024: Nano Letters