Topological Crystalline Metal in Orthorhombic Perovskite Iridates

Understand

Since topological insulators were theoretically predicted and experimentally observed in semiconductors with strong spin-orbit coupling, more and more attention has been drawn to topological materials which host exotic surface states.

• These surface excitations are stable against perturbations since they are protected by global or spatial/lattice symmetries.
• Succeeded in achieving various topological insulators, a tempting challenge now is to search for metallic materials with novel topological properties.
• Here we predict that orthorhombic perovskite iridates realize a new class of metals dubbed topological crystalline metals, which support zero-energy surface states protected by certain lattice symmetry.