Pressuring the low-temperature orthorhombic phase with a non-trivial topological state of Ru₂Sn₃ to room temperature

We report high-pressure studies of the structural stability of Ru₂Sn₃, a new type of three-dimensional topological insulator (3D-TI) with unique quasi-one-dimensional Dirac electron states throughout the surface Brillouin zone of its one-atmosphere low-temperature orthorhombic form. Our in-situ high-pressure synchrotron x-ray diffraction and electrical resistance measurements reveal that upon increasing pressure the tetragonal-to-orthorhombic phase shifts to higher temperature. We find that the stability of the orthorhombic phase that hosts the non-trivial topological ground state can be pushed up to room temperature by an applied pressure of ∼ 20 GPa. This is in contrast with the commonly known 3D-TIs whose ground state is usually destroyed under pressure. Our results indicate that pressure provides a possible pathway for realizing a room temperature topological insulating state in Ru₂Sn₃.