Anatomy

Combinatorics

Physics

Brillouin zone

Topology (electrical circuits)

Ideal (ethics)

Symmetry (geometry)

Mathematics

Surface phonon

Political science

Neutrino

Surface (topology)

Phonon

Geometry

Condensed matter physics

Dirac (video compression format)

Quantum mechanics

Degenerate energy levels

NODAL

Medicine

Physical review. B./Physical review. B

By using first-principles calculations and symmetry analysis, we uncover that the rubidium-catena-telluridoaurate-family materials in space group (SG) 51 can exhibit ideal nodal-surface phonons separately in the three-dimensional Brillouin zone, characterized by nearly flat phonon bands in their phonon spectra. The nodal surfaces are protected both by the screw rotation symmetry and the time reversal symmetry. Moreover, our theoretical calculations demonstrate that the nodal surfaces are composed by twofold degenerate nodal points, which can form a straight singularity nodal line in the (001) surface, and that the (001) surface states display Dirac-type crossings and surface flat-band phononic states, confirming the topologically nontrivial nature of nodal-surface phonons. Our findings not only support that another class of nodal phononic states, i.e., one-node surface phonons, can exist in realistic materials in 230 SGs, but also put forward an effective way to search for nodal-surface phonons.

Ideal topological nodal-surface phonons in RbTeAu-family materials