Physicists from the University of Jyväskylä and Aalto University in Finland have successfully created a two dimensional topological crystalline insulator, marking the first experimental realization of a quantum material that scientists had predicted for more than a decade. Until now, attempts to produce it had been held back by difficulties in developing the right materials.
The breakthrough was led by Associate Professor Kezilbeiek Shawulienu in collaboration with Aalto University researchers, including Professor Peter Liljeroth and Professor Jose Lado. The team fabricated the material by growing an atomically thin film consisting of just two layers of tin telluride (SnTe) on top of a niobium diselenide (NbSe2) substrate.
Atomically Thin Crystal Reveals Unique Quantum States
To examine the material's properties, the researchers used molecular beam epitaxy together with low temperature scanning tunneling microscopy, allowing them to probe its electronic behavior with atomic level precision.
Their measurements revealed pairs of conducting edge states, a defining feature of topological crystalline insulators. These special pathways allow electrons to travel along the edges of the material and are protected by the symmetry of the crystal lattice.
