Institute for Materials Science and Max Bergmann Center of Biomaterials, Dresden University of Technology, Dresden 01062, Germany.
Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
J Chem Phys. 2023 Jul 14;159(2). doi: 10.1063/5.0156347.
We address the electron-spin-phonon coupling in an effective model Hamiltonian for DNA to assess its role in spin transfer involved in the Chiral-Induced Spin Selectivity (CISS) effect. The envelope function approach is used to describe semiclassical electron transfer in a tight-binding model of DNA at half filling in the presence of intrinsic spin-orbit coupling. Spin-phonon coupling arises from the orbital-configuration dependence of the spin-orbit interaction. We find spin-phonon coupling only for the acoustic modes, while the optical modes exhibit electron-phonon interaction without coupling to spin. We derive an effective Hamiltonian whose eigenstates carry spin currents that are protected by spin-inactive stretching optical modes. As optical phonons interact more strongly than acoustic phonons, side buckling and tilting optical base modes will be more strongly associated with decoherence, which allows for the two terminal spin filtering effects found in CISS.
我们在 DNA 的有效模型哈密顿量中研究电子-自旋-声子耦合，以评估其在涉及手性诱导自旋选择（CISS）效应的自旋转移中的作用。在存在本征自旋轨道耦合的情况下，我们使用包络函数方法来描述 DNA 的紧束缚模型在半填充时的半经典电子转移。自旋-声子耦合源于自旋轨道相互作用的轨道构型依赖性。我们发现只有声学模式存在自旋-声子耦合，而光学模式表现出电子-声子相互作用，但不与自旋耦合。我们推导出一个有效哈密顿量，其本征态携带自旋流，这些自旋流受到自旋非活性拉伸光学模式的保护。由于光学声子比声学声子相互作用更强，因此侧弯曲和倾斜的光学碱基模式将与退相干更强烈相关，这允许在 CISS 中发现的两个终端自旋过滤效应。
