论文标题
评论“三维高阶拓扑绝缘子的库仑不稳定性”
Comment on "Coulomb Instabilities of a Three-Dimensional Higher-Order Topological Insulator"
论文作者
论文摘要
基于Zhao等人[Phys。莱特牧师。 127，176601（2021）]声称，三维二阶拓扑绝缘子（SOTIS）始终对库仑相互作用不稳定，因此它们将经历拓扑相变为拓扑绝缘子（TIS）或正常绝缘体。尽管本文中的计算是正确的，但关于从SOTI到Ti的拓扑相变的结论是不正确的。这个错误结论的原因在于作者使用错误的标准来识别相变。在此评论中，我们想提醒，要找到从SOTI到Ti的可能过渡，适当的数量是符号质量差距$ m_ \ textrm {surf} $ for Surface状态。通过检查其在RG方法中的行为，SOTI对弱库仑相互作用的稳定性得到了证明。
Based on renormalization-group (RG) calculations, a recent Letter by Zhao et al [Phys. Rev. Lett. 127, 176601 (2021)] claimed that three-dimensional second-order topological insulators (SOTIs) are always unstable to the Coulomb interaction and they will thus undergo topological phase transitions to either topological insulators (TIs) or normal insulators. While the calculations in this paper are correct, the conclusion about the topological phase transition from SOTI to TI is not true. The reason behind this false conclusion lies in that the authors use a wrong criterion to identify the phase transition. In this Comment we would like to remind that, to locate the possible transitions from SOTI to TI, an appropriate quantity is the sign-changing mass gap $m_\textrm{surf}$ for the surface states. By examining its behavior within RG approach, the stability of SOTI against weak Coulomb interactions is demonstrated.
