论文标题
电子在温暖的物质和非理想的血浆条件下电子的能量损失和摩擦特性
Energy loss and friction characteristics of electrons at warm dense matter and non-ideal dense plasma conditions
论文作者
论文摘要
我们研究了暖密度物质（WDM）和致密等离子体的能源损失特征，这些血浆集中在电子相关性的影响上。我们分析的基础是基于静态局部场校正（LFC）的基于量子量蒙特卡洛（QMC）的量子量量蒙特卡洛（QMC）[Dornheim等，J。Chem。物理。 151，194104（2019）]，它在所考虑的参数下提供了电子气体的动态密度响应函数的准确描述。我们专注于由于电子，摩擦函数和散落速率引起的极化引起的停止功率。此外，我们计算摩擦系数，该系数构成了离子足够的langevin动力学模拟的关键量。考虑到具有部分退化电子的典型实验性WDM参数，我们发现摩擦系数的顺序为$γ/ω__{pi} = 0.01 $，其中$ω_{pi} $是离子plasma频率。通过将基于QMC的数据与随机相近似（RPA），Mermin介电函数和Singwi-Tosi-Tosi-Land-Sjölander（STLS）近似的结果进行比较来进行该分析。据揭示，广泛使用的松弛时间近似（Mermin介电函数）在描述相关的部分退化电子的能量损失特性方面存在严重限制。此外，通过将基于QMC的数据与使用STLS获得的结果进行比较，我们发现能量损失属性对静态LFC的不准确性并不敏感，该静态LFC在大波数$ k/k_ {f}> 2 $中（$ k_f $ a $ k_f $是通常的fermi wave数字），但这是$ k/k_的正确描述。
We investigate the energy loss characteristics of warm dense matter (WDM) and dense plasmas concentrating on the influence of electronic correlations. The basis for our analysis is a recently developed ab initio Quantum Monte-Carlo (QMC) based machine-learning representation of the static local field correction (LFC) [Dornheim et al., J. Chem. Phys. 151, 194104 (2019)], which provides an accurate description of the dynamical density response function of the electron gas at the considered parameters. We focus on the polarization-induced stopping power due to free electrons, the friction function, and the straggling rate. In addition, we compute the friction coefficient which constitutes a key quantity for the adequate Langevin dynamics simulation of ions. Considering typical experimental WDM parameters with partially degenerate electrons, we find that the friction coefficient is of the order of $γ/ω_{pi}=0.01$, where $ω_{pi}$ is the ionic plasma frequency. This analysis is performed by comparing QMC based data to results from the random phase approximation (RPA), the Mermin dielectric function, and the Singwi-Tosi-Land-Sjölander (STLS) approximation. It is revealed that the widely used relaxation time approximation (Mermin dielectric function) has severe limitations regarding the description of the energy loss properties of correlated partially degenerate electrons. Moreover, by comparing QMC based data with the results obtained using STLS, we find that energy loss properties are not sensitive to the inaccuracy of the static LFC at large wave numbers $k/k_{F}>2$ (with $k_F$ being the usual Fermi wave number), but that a correct description of the static LFC at $k/k_{F}\lesssim 1.5$ is important.
