论文标题
远程依赖时间依赖的玻尔兹曼碰撞操作员的数值方案:一级二级动量离散和自适应时间踏上
Numerical scheme for the far-out-of-equilibrium time-dependent Boltzmann collision operator: 1D second-degree momentum discretisation and adaptive time stepping
论文作者
论文摘要
量子材料中远程平衡的热化动力学的研究,包括不同类型的准颗粒的动力学,变得越来越重要。但是,在Boltzmann方法中,完整的量子机械处理或散射积分的溶液的固有复杂性显着限制了该结构域的进展。在以前的工作中,我们开发了一个求解器来计算玻尔兹曼方程中的散射积分。求解器没有任何近似值(没有散射算子的线性化,没有接近平衡的近似,完全非分析的分散体,对Pauli因子的全部说明,并且对低阶散射没有限制)\ Cite {Michael}。在这里,我们通过扩展到二级基础功能来扩展它以实现高阶动量空间融合。CWE进一步使用自适应时间步进,从而实现了数值性能的显着改善。此外,我们显示自适应时间步进可以防止在Boltzmann散射操作员的时间传播中固有的不稳定性。这项工作使整个Boltzmann散射操作员有效,稳定且最少依赖人类监督的数值时间传播。
Study of far-from-equilibrium thermalization dynamics in quantum materials, including the dynamics of different types of quasiparticles, is becoming increasingly crucial. However, the inherent complexity of either the full quantum mechanical treatment or the solution of the scattering integral in the Boltzmann approach, has significantly limited the progress in this domain. In our previous work we had developed a solver to calculate the scattering integral in the Boltzmann equation. The solver is free of any approximation (no linearisation of the scattering operator, no close-to-equilibrium approximation, full non-analytic dispersions, full account of Pauli factors, and no limit to low order scattering) \cite{Michael}. Here we extend it to achieve a higher order momentum space convergence by extending to second degree basis functions.cWe further use an adaptive time stepper, achieving a significant improvement in the numerical performance. Moreover we show adaptive time stepping can prevent intrinsic instabilities in the time propagation of the Boltzmann scattering operator. This work makes the numerical time propagation of the full Boltzmann scattering operator efficient, stable and minimally reliant on human supervision.