We have determined the electron–phonon interaction in type II Dirac semimetallic 1T-PdTe₂ by means of helium atom scattering. While 1T-PdTe₂ is isostructural with 1T-PtTe₂, only the former is superconductor. The difference can be traced to the substantially larger value of the electron–phonon coupling in 1T-PdTe₂, λ = 0.58, obtained from the Debye-Waller attenuation of the He specular peak. With this value and the surface Debye temperature, Θ_D = 106.2 K, we have figured out the superconducting critical temperature, T_c = 1.83 K given by the BCS theory, which is in good agreement with T_c = (1.95 ± 0.03) K obtained with low-temperature scanning tunneling microscopy. The value of the effective mass related to Θ_D indicates that the large electron–phonon coupling in 1T-PdTe₂ is due to coupling, not only with the zone-center optical mode O₂ at 9.2 meV, as proposed in a recent theoretical study, but also with the zone-boundary acoustic mode LA. Our results suggest that the topological states of a Dirac cone play a negligible role on the onset of superconductivity.

我们已经通过氦原子散射确定了II型Dirac半金属1T-PdTe _2中的电子-声子相互作用。虽然1T-PdTe ₂是同构与1T-PtTe ₂，只有前者的超导体。可以追溯到1T-PdTe _2中电子-声子耦合的较大值，λ  = 0.58，这是从He镜面反射峰的Debye-Waller衰减获得的。随着该值和表面温度德拜，Θ _d  = 106.2 K，我们已经想出超导临界温度，Ť _Ç  =由BCS理论，这是在具有良好的协议给定的1.83ķ Ť _Ç ＝（1.95±0.03）K是用低温扫描隧道显微镜得到的。有关Θ的有效质量的值_d表示在1T-PdTe大电子-声子耦合₂是由于耦合，不仅与该区域中心的光学模式ö ₂在9.2兆电子伏，如在最近的理论研究中提出，也可以使用区域边界声学模式LA。我们的研究结果表明，狄拉克锥的拓扑状态在超导性的发生中起着微不足道的作用。