Shimada Nao H, Minamitani Emi, Watanabe Satoshi
Department of Materials Engineering, The University of Tokyo, Japan.
Institute for Molecular Science, Japan.
J Phys Condens Matter. 2020 Aug 4;32(43). doi: 10.1088/1361-648X/aba674.
We investigated the possibility of superconductivity in monolayer hexagonal boron nitride (h-BN) doped using group-1 (Li, Na, K) and group-2 (Be, Mg, Ca, Sr, Ba) atoms viacalculations. Consequently, we reveal that Sr- and Ba-doped monolayer h-BN and Ca-doped monolayer h-BN with 3.5% tensile strain are energetically stable and become superconductors with superconducting transition temperature (Tc) values of 5.83, 1.53, and 10.7 K, respectively, which are considerably higher than those of Ca-, Sr-, and Ba-doped graphene. In addition, the momentum-resolved electron-phonon coupling (EPC) constant shows that the scattering among intrinsic π* electrons around the Γ point governs Tc. The scattering process is mediated by the low-energy vibration of the adsorbate. Moreover, compared with graphene, the stronger adsorbate-substrate interaction and lower symmetry in h-BN are critical for enhancing the EPC in doped h-BN.
我们通过计算研究了用第1族（锂、钠、钾）和第2族（铍、镁、钙、锶、钡）原子掺杂的单层六方氮化硼（h-BN）中存在超导性的可能性。结果表明，掺锶和掺钡的单层h-BN以及具有3.5%拉伸应变的掺钙单层h-BN在能量上是稳定的，并且分别成为超导转变温度（Tc）值为5.83、1.53和10.7 K的超导体，这些值远高于掺钙、掺锶和掺钡的石墨烯。此外，动量分辨电子-声子耦合（EPC）常数表明，Γ点附近本征π*电子之间的散射决定了Tc。散射过程由吸附质的低能振动介导。此外，与石墨烯相比，h-BN中更强的吸附质-衬底相互作用和更低的对称性对于增强掺杂h-BN中的EPC至关重要。
