论文标题
通过自然评估的半导体纳米颗粒的电子结构的虚构时间路径积分
Electronic structure of semiconductor nanoparticles from stochastic evaluation of imaginary-time path integral
论文作者
论文摘要
在Kohn-Sham轨道基础基础基础上，半导体纳米颗粒中电子的想象路径积分有轻度的费米符号问题，并且可以通过标准随机方法进行评估。硅氢氢化的纳米晶体的模拟证明了这一点，例如$ si_ {35} h_ {36}，〜si_ {87} h_ {76}，〜si_ {147}价电子和尺寸$ 1.0-2.4〜nm $的范围，利用密度功能理论模拟的输出。我们发现，仅使用领先的阶极化项近似式费米亚动作会导致功能积分中的正定限定集成，并且它是完整作用的良好近似值。我们在这些纳米晶体中计算假想的时时间传播器，并提取低洼电子和孔水平的能量。我们的准粒子差距预测与使用$ G_0W_0 $技术的高精度计算结果一致。这种形式主义可以扩展到更复杂的激发态，例如激发剂和Trions。
In the Kohn-Sham orbital basis imaginary-time path integral for electrons in a semiconductor nanoparticle has a mild Fermion sign problem and is amenable to evaluation by the standard stochastic methods. This is evidenced by the simulations of silicon hydrogen-passivated nanocrystals, such as $Si_{35}H_{36},~Si_{87}H_{76},~Si_{147}H_{100}$ and $Si_{293}H_{172},$ which contain $176$ to $1344$ valence electrons and range in size $1.0 - 2.4~nm$, utilizing the output of density functional theory simulations. We find that approximating Fermion action with just the leading order polarization term results in a positive-definite integrand in the functional integral, and that it is a good approximation of the full action. We compute imaginary-time electron propagators in these nanocrystals and extract the energies of low-lying electron and hole levels. Our quasiparticle gap predictions agree with the results of high-precision calculations using $G_0W_0$ technique. This formalism can be extended to calculations of more complex excited states, such as excitons and trions.
