Szczegóły publikacji

Shandite with Ni₃Pb₂S₂ chemical formula and Rm symmetry contains the kagome sublattice formed by transition metal atoms. Recent experimental results confirmed the possibility of successfully synthesizing Pd₃Pb₂Ch₂ (Ch=S,Se) with the same structure. This paper theoretically investigates the dynamical properties of such compounds. Furthermore, we study the possibility of realizing Pt₃Pb₂Ch₂ with the shandite structure. This study shows that the Pd₃Pb₂Ch₂ and Pt₃Pb₂S₂ are stable with Rm symmetry. In the case of Pt₃Pb₂S₂, there is a soft mode, which is the source of the structural phase transition from Rm to Rc symmetry, related to the distortion within the kagome sublattice. This study discusses realized phonon nodal lines in bulk phonon dispersions in upper frequency modes. It shows that the shandite structure can host phonon surface states, with a strong dependence on the type of surface. Additionally, chiral phonons with circular motion of the Pb atoms around the equilibrium position are realized.

Shandite with Ni₃Pb₂S₂ chemical formula and Rm symmetry contains the kagome sublattice formed by transition metal atoms. Recent experimental results confirmed the possibility of successfully synthesizing Pd₃Pb₂Ch₂ (Ch=S,Se) with the same structure. This paper theoretically investigates the dynamical properties of such compounds. Furthermore, we study the possibility of realizing Pt₃Pb₂Ch₂ with the shandite structure. This study shows that the Pd₃Pb₂Ch₂ and Pt₃Pb₂S₂ are stable with Rm symmetry. In the case of Pt₃Pb₂S₂, there is a soft mode, which is the source of the structural phase transition from Rm to Rc symmetry, related to the distortion within the kagome sublattice. This study discusses realized phonon nodal lines in bulk phonon dispersions in upper frequency modes. It shows that the shandite structure can host phonon surface states, with a strong dependence on the type of surface. Additionally, chiral phonons with circular motion of the Pb atoms around the equilibrium position are realized.