  Condensed matter systems contain both fermionic and bosonic quasiparticles.
Owing to the constraint imposed by the Fermi level, ideal material candidate
for the emergent particles with higher-dimensional degeneracy manifold (i.e.,
nodal lines and nodal surfaces) has not been found in electronic systems. This
paper demonstrates that according to the first-principle calculations and
symmetry analysis, realistic ternary nitride Li$_6$WN$_4$ features ideal
(nearly flat) nodal-surface and nodal-line structures in its phonon spectra.
These nodal degeneracies are shaped like lanterns, and their existence is
guaranteed by nonsymmorphic symmetry. The corresponding topological phonon
surface state covers exactly half the surface Brillouin zone (BZ) and can
thereby be distinguished from those of conventional nodal-line and
nodal-surface semimetals. The results of our study demonstrate the existence of
ideal lantern-like phonons in realistic materials, which enriches the
classification of topological quantum phases and provides a good basis for
investigating the interaction between nodal-line and nodal-surface phonons in a
single material.
