Scientists design and synthesize a new layered air-stable topological crystalline insulator candidate

Exploring novel topological materials and related phase transitions has been a central research theme in condensed matter physics and materials science. Topological materials with nontrivial anti-band crossings have attracted much attention. Hourglass fermion surface state, located at the vertex in the neck of an hourglass-like dispersion, enables exploration of remarkable topological phases, such as the hourglass Weyl point, movement along high symmetry lines, and hourglass nodal chains or net....