Fermiology and transport properties of the candidate topological crystalline insulator SrAg4Sb2

Inspired by the nonmagnetic topological materials database, the authors investigated the 3D fermiology and band topology of the Topological Crystalline Insulator (TCI) candidate SrAg₄Sb₂. The fermiology, revealed by angular-dependent quantum oscillations, shows excellent agreement with first-principles calculations. Symmetry and topology analysis result in two potential sets of topological invariants, suggesting the emergence of crystal-symmetry-protected gapless Dirac surface states either on the as-grown ab planes or on both the ab planes and as-grown mirror planes. Their findings provide evidence that SrAg₄Sb₂ is a promising TCI for exploring topological surface states protected by crystal symmetry.