AI 中文总结
研究弯曲硅卡戈梅晶格，通过双轴张力控制晶格动力学与电子色散，利用应变耦合热亚稳性等，实现应变控制晶体 - 非晶转变和平带调谐，是应变控制平带和电子关联物理的候选平台。
AI 中文摘要
元素二维材料中的电子平带为电子相互作用与抑制的动能竞争提供了一个有吸引力的环境。本文提出了一种弯曲的硅卡戈梅晶格（SiKL），它是由键联的Si₃三角形和十二边形孔组成的未功能化六原子单层。其平面母体在费米能级附近有一个无色散的科恩 - 沙姆带，但对外平面畸变不稳定。跟随三个软区中心声子并松弛位移结构产生两种近乎简并的弯曲形式。高弯曲形式在费米能级附近保留了一个部分平坦的源自卡戈梅的带。双轴张力控制晶格动力学和电子色散：在10%应变下，带宽显著减小，态密度峰值接近费米能级，最软的声子变硬。在315K时，6×6的从头算分子动力学表明未应变网络无序化而应变网络保持有序，表明有限温度亚稳性。36×36片材的50纳秒经典分子动力学揭示了在2%应变附近的应变控制晶体 - 非晶转变和局部键合交叉。低应变轨迹显示逐渐的两阶段无序化；高应变经历突然的一阶样崩塌，在10%应变下转变温度达到约600K。一个探索性的Ag(111)衬底模型表明外延失配可以提供相当的张力，保留窄的SiKL带，并在室温以上保持晶体有序。与主要针对传统半导体的钝化或混合晶格硅卡戈梅提议不同，SiKL是元素性的，仅使用应变来耦合热亚稳性、键重排和近费米平带调谐。弯曲的SiKL是应变控制平带和电子关联物理的候选平台。
英文摘要
Electronic flat bands in an elemental two-dimensional material provide an attractive setting for electron interactions competing with suppressed kinetic energy. Here we propose a buckled silicon kagome lattice (SiKL), an unfunctionalized six-atom monolayer of bond-linked Si$_3$ triangles and dodecagonal pores. Its planar parent hosts a dispersionless Kohn--Sham band near the Fermi level but is unstable to out-of-plane distortions. Following three soft zone-centre phonons and relaxing displaced structures yields two nearly degenerate buckled forms. The high-buckling form retains a partially flat kagome-derived band near the Fermi level. Biaxial tension controls lattice dynamics and electronic dispersion: at 10% strain, the bandwidth decreases significantly, the density-of-states peak approaches the Fermi level, and the softest phonon hardens. At 315 K, $6\times6$ ab initio MD shows the unstrained network disordering while the strained network remains ordered, indicating finite-temperature metastability. Fifty-nanosecond classical MD of $36\times36$ sheets reveals a strain-controlled crystalline--amorphous transition and local-bonding crossover near 2% strain. Low-strain trajectories show gradual, two-stage disordering; higher strains undergo an abrupt, first-order-like collapse, with the transition temperature reaching approximately 600 K at 10% strain. An exploratory Ag(111) substrate model suggests epitaxial mismatch could supply comparable tension, retain a narrow SiKL band, and preserve crystalline order above room temperature. Unlike passivated or hybrid-lattice silicon kagome proposals aimed mainly at conventional semiconductors, SiKL is elemental and uses strain alone to couple thermal metastability, bond rearrangement, and near-Fermi flat-band tuning. Buckled SiKL is a candidate platform for strain-controlled flat-band and electronic correlation physics.
