Ideal nodal-net, nodal-chain, and nodal-cage phonons in some realistic materials

Abstract

The topological interpretation of phonons provides a new platform for new concepts in phonon physics. While reports on topological electronic excitations are plenty, the number of reports on phonons is...

Complex nodal structure phonons formed by open and closed nodal lines in CoAsS and Na2CuP solids

“…1(b), the nodal lines on the k x = 0, k y = 0, and k y = π planes have the π value of the Berry phase, indicating that they are topologically nontrivial. 50,51,53 Typically, the topologically nontrivial nodal line tends to induce surface states, which topic is addressed in detail later in Section 5 concerning CoAsS.…”

“…29 Compared to the large number of studies in the field of twodimensional (2D) and three-dimensional (3D) topological electronic materials, the research concerning 3D topological phononic materials has only been initiated in the past few years. Roughly, the topological phonons in 3D solids can be divided into nodal point phonons, [36][37][38][39][40][41][42][43][44][45] nodal line phonons, [46][47][48][49][50][51][52][53][54][55][56][57][58] and nodal surface phonons, [59][60][61][62] respectively, corresponding to zerodimensional (0D), one-dimensional (1D), and 2D phonon band degeneracies in the 3D Brillouin zone (BZ). Note that the types of nodal line phonons are more diverse than those of nodal points and nodal surface phonons.…”

Cubic Ca3I3P with ideal charge-two triple point

“…The current study of crystal topology has even been further extended to bosons, including phonons, photons, and magnons. Phonons [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] can be a perfect platform for realizing these quasiparticles owing to their unique device applications and the advantages of whole frequency range observation. For example, in the phonon dispersion of three-dimensional-SiO 2 , Wang et al [40] proposed a topological triangular Weyl complex made up of one double Weyl point and two single Weyl points.…”

Ideal phononic charge-two nodal point and long nontrivial surface arcs in Na2Zn2O3

“…Recently, there has been great interest in exploring topological quasiparticles in phonons [1], which describe the atomic lattice vibrations in solids. So far, a number of materials hosting Weyl point phonons [2][3][4][5][6][7][8][9][10], Dirac point phonons [11,12], triple degenerate nodal point phonons [13,14], sixfold degenerate nodal point phonons [15,16], nodal line phonons [17][18][19][20][21][22][23][24][25][26][27][28][29][30] and nodal surfaces phonons [31][32][33] have been discovered. Compared with chiral fermions in electronic systems, chiral phonons exist without spin-orbital coupling.…”