Topological electron and phonon nodal line in superconductor TLS-Mo2Te

Abstract

The interaction between topological electronic and nontrivial phononic states offers a promising route to superconducting mechanisms, yet material platforms that host both are exceedingly rare. Here, we identify bulk triple-layer-stacked bulk Mo2Te (TLS-Mo2Te) as a topological nodal line semimetal in the spinless limit. Concurrently, it features stable topological optical phonon modes. Our calculations reveal that the Mo2Te system exhibits multiple nodal lines in the absence of spin–orbit coupling (SOC), and turns into a compensation semimetal with a nontrivial topological invariant when SOC is included. Similarly, the phonon spectrum reveals clear nodal lines, closely associated with specific vibrational modes. Notably, the intermediate coupling between the electronic states near the Fermi level and optical phonon modes (which also exhibit topological nodal lines) drives the system into a conventional superconducting state with a predicted critical temperature (Tc) of ∼4.56 K. Our work not only predicts a new superconducting material with coexistence of electronic and phononic topological nodal lines, but also establishes TLS-Mo2Te as a platform for studying topological optical phonon-induced superconductivity.