论文标题
GW时空法：固体氢的能量带隙
GW space-time method: Energy band-gap of solid hydrogen
论文作者
论文摘要
我们在有限温度下实施了GW时空方法，其中绿色的功能G和筛选的库仑相互作用w在合适的网格和假想时间内在Chebyshev多项式方面表示，特别注意控制该表示的系统误差。在通过对硅和锗的规范应用验证了该技术后，我们将其应用于六边形固体氢中的带隙，并从密度函数近似值获得的裸绿色功能以及在随机相位近似（RPA）中筛选的相互作用获得。从完整绿色功能的渐近衰减中获得的带隙结果而不诉诸于分析性延续，这表明高于270 GPA的固体氢无法采用六边形粘合式包装（HCP）结构。该方法以足够精确的态度将该方法存储在记忆中的完整G和W功能的能力对于其随后的扩展即通过示意蒙特卡洛算法包括示意序列的较高级数至关重要。
We implement the GW space-time method at finite temperatures, in which the Green's function G and the screened Coulomb interaction W are represented in the real space on a suitable mesh and in imaginary time in terms of Chebyshev polynomials, paying particular attention to controlling systematic errors of the representation. Having validated the technique by the canonical application to silicon and germanium, we apply it to calculation of band gaps in hexagonal solid hydrogen with the bare Green's function obtained from density functional approximation and the interaction screened within the random phase approximation (RPA). The band gap results, obtained from the asymptotic decay of the full Green's function without resorting to analytic continuation, suggest that the solid hydrogen above 270 GPa can not adopt the hexagonal-closed-pack (hcp) structure. The demonstrated ability of the method to store the full G and W functions in memory with sufficient accuracy is crucial for its subsequent extensions to include higher orders of the diagrammatic series by means of diagrammatic Monte Carlo algorithms.
