Theoretical Studies of Chirality-Induced Spin Selectivity

手性诱导自旋选择性的理论研究

• 批准号: 442940777
• 负责人: Professor Dr. Gianaurelio Cuniberti
• 金额: --
• 依托单位: Institut für Werkstoffwissenschaft
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/442940777?language=en
• 关键词: Theoretical; Studies; Chirality; Induced; Spin

Exploiting the spin degree of freedom to transfer information or perform logic operations builds the basis of spintronics. Currently, the majority of existing spintronic devices are based on inorganic materials. However, using organic molecules in spintronics, though very challenging, would offer many advantages such as the possibility for chemically tuning the spin-dependent response as well as their inexpensive synthesis in large amounts. For molecules lacking an intrinsic magnetic response, strong spin-dependent properties may not be expected. Surprisingly, it was shown experimentally a few years ago that monolayers of double-stranded DNA (dsDNA) oligomers can act as strong spin filters. A very suggestive hypothesis has been proposed that spin selectivity is closely related to the helical symmetry of the molecules studied so far (dsDNA, bacteriorhodopsine, helical oligopeptides, helicene). In other words, it seems that the helical shape (besides the possible presence of chiral centers) is largely responsible for the observed phenomenon. These results can have profound implications not only for the design of novel, organic or bio-inspired spintronic devices but also shed new light on electron transfer in biologically relevant molecules. This novel phenomenon has been called Chirality-Induced Spin Selectivity (CISS) effect. In this proposal we are aiming at theoretically exploring the CISS effect from various perspectives with the goal of shedding additional light on its basis. The reference point will be molecular systems displaying helical symmetry so that it will be possible to complement model-based studies with electronic structure investigations in realistic systems. This will help to reduce the arbitrariness in the choice of the relevant model parameters. We expect that the results obtained in the current proposal will not only be of fundamental interest in understanding the interplay between geometry and spin-dependent properties but also serve as a guide and motivation for further experimental studies.

利用自旋的自由度来传递信息或执行逻辑运算，是自旋电子学的基础。目前，大多数现有的自旋电子器件是基于无机材料。然而，在自旋电子学中使用有机分子虽然非常具有挑战性，但将提供许多优点，例如化学调谐自旋依赖性响应的可能性以及大量廉价的合成。对于缺乏内禀磁响应的分子，可能无法预期强的自旋相关性质。令人惊讶的是，几年前的实验表明，双链DNA（dsDNA）低聚物的单层可以作为强自旋过滤器。一个非常有启发性的假设已经提出，自旋选择性是密切相关的螺旋对称性的分子研究到目前为止（双链DNA，bacteriorhodopsine，螺旋寡肽，helicene）。换句话说，螺旋形状（除了可能存在手性中心）似乎是观察到的现象的主要原因。这些结果不仅对新型有机或生物自旋电子器件的设计具有深远的意义，而且还为生物相关分子中的电子转移提供了新的思路。这种新的现象被称为手性诱导自旋选择性（CISS）效应。在这个建议中，我们的目标是从理论上探讨CISS效应从不同的角度，其目标是脱落更多的光在其基础上。参考点将是显示螺旋对称的分子系统，以便有可能补充基于模型的研究与现实系统中的电子结构调查。这将有助于减少相关模型参数选择的任意性。我们希望在目前的建议中获得的结果将不仅是理解几何和自旋相关的属性之间的相互作用的根本利益，但也作为进一步的实验研究的指导和动机。