Conformational change-modulated spin transport at single-molecule level in carbon systems

Controlling the spin transport at the single-molecule level, especially without the use of ferromagnetic contacts, becomes a focus of research in spintronics. Inspired by the progress on atomic-level molecular synthesis, through first-principles calculations, we investigate the spin-dependent electronic transport of graphene nanoflakes with side-bonded functional groups, contacted by atomic carbon chain electrodes. It is found that, by rotating the functional group, the spin polarization of the transmission at the Fermi level could be switched between completely polarized and unpolarized states. Moreover, the transition between spin-up and spin-down polarized states can also be achieved, operating as a dual-spin filter. Further analysis shows that, it is the spin-dependent shift of density of states, caused by the rotation, that triggers the shift of transmission peaks, and then results in the variation of spin polarization. Such a feature is found to be robust to the length of the nanoflake and the electrode material, showing great application potential. Those findings may throw light on the development of spintronic devices.     

基于复杂工程问题驱动的锂离子电池综合实验设计及实践

在高等学校工程教育认证“解决复杂工程问题能力”驱动下,大学物理实验课程的选题内容和模式在不断改革和创新。锂离子电池技术作为当下新能源科技革命的代表,具有学科交叉性和综合性,满足复杂工程问题的多项特征。文章探讨了将锂离子电池技术引入大学物理实验教学的优势和可行性,并提炼出锂离子电池综合实验设计的具体实施方案,为提高学生解决复杂工程问题的能力,培养复合创新型大学生奠定基础。