Huygens-Kamerlingh Onnes Laboratory, Leiden University, NL-2333CA Leiden, Netherlands.
Department of Condensed Matter Physics, Charles University, 121 16 Praha 2, Czech Republic.
J Chem Phys. 2023 Jul 14;159(2). doi: 10.1063/5.0156316.
Chirality-induced spin selectivity has been reported in many experiments, but a generally accepted theoretical explanation has not yet been proposed. Here, we introduce a simple model system of a straight cylindrical free-electron wire containing a helical string of atomic scattering centers with spin-orbit interaction. The advantage of this simple model is that it allows deriving analytical expressions for the spin scattering rates, such that the origin of the effect can be easily followed. We find that spin-selective scattering can be viewed as resulting from the constructive interference of partial waves scattered by the spin-orbit terms. We demonstrate that forward scattering rates are independent of spin, while back scattering is spin dependent over wide windows of energy. Although the model does not represent the full details of electron transmission through chiral molecules, it clearly reveals a mechanism that could operate in chiral systems.
手性诱导的自旋选择性在许多实验中都有报道，但尚未提出普遍接受的理论解释。在这里，我们引入了一个简单的模型系统，即一个包含具有自旋轨道相互作用的原子散射中心螺旋线的直圆柱自由电子线。这个简单模型的优点是，它允许推导出自旋散射率的解析表达式，从而可以很容易地跟踪效应的起源。我们发现，自旋选择性散射可以看作是由自旋轨道项散射的部分波的相长干涉引起的。我们证明，前向散射率与自旋无关，而反向散射在宽能隙窗口中是自旋相关的。尽管该模型不能完全代表手性分子中电子传输的详细情况，但它清楚地揭示了在手性系统中可能起作用的机制。
