DNA分子的量子输运性质研究

DNA is regarded as one of the leading candidates in the field of molecular electronics, because of its unique features including molecular recognition, self-assembly property, and helical structure. Besides, DNA has applications in nanotechnology and molecular electronics. Very recently, the quantum transport properties of DNA molecules have been attracting extensive attention among different scientific communities. For instance, it was reported in a recent experiment that DNA can function as a molecular rectifier which is considered as the smallest one in the world. On the basis of our previous works and recent experimental progress, we study the quantum transport properties of DNA molecules and its derivatives. The research subjects are listed in the following. 1) A theoretical model which could explain various DNA charge transport experiments will be constructed. The charge transport through DNA molecules in realistic environments is then studied using multiscale techniques. Here, we focus on the influence of base sequence, temperature, and gene mutation. 2) The topological states of different DNA molecules will be investigated by taking into account the influence of temperature, molecular structure, and impurity. We hope to find several DNA molecules which display very robust topological states. 3) The thermoelectric properties of DNA molecules will be studied and the way to improve their thermoelectric efficiency will be shown. 4) The charge transport properties of DNA derivatives will be investigated and their transport ability will be controlled. Through these studies, we hope to understand the underlying quantum transport mechanism of DNA molecules and find out novel physical phenomena which are related to the quantum transport properties of DNA molecules. Our study may help for designing DNA-based molecular devices from the theoretical aspect.

由于独特的分子识别性能、自组装性质和螺旋结构，DNA因此成为分子电子学领域的重要研究对象，具有实际应用价值。最近，DNA分子的量子输运引起人们的广泛关注，如实验报道DNA是目前世界上最小的分子整流器件等。基于前期工作基础并结合最新实验进展，本项目研究DNA分子及其衍生物的量子输运性质，具体包括：1）构建能统一解释各种DNA分子电荷输运实验的理论模型，利用多尺度方法，模拟真实环境中DNA分子的电荷输运，重点考察碱基排序、温度、基因突变等因素的影响；2）研究温度、分子结构、杂质等因素对各种DNA分子拓扑态的影响，找到具有稳定拓扑态的DNA分子；3）研究DNA分子的热电性质，发现提高DNA分子热电输运效率的途径；4）研究、调控DNA衍生物的电荷输运性能。通过本项目研究，能深入了解DNA分子的量子输运机制，发现若干个与DNA分子量子输运有关的新奇物理现象，为设计DNA分子电子学器件提供理论依据。

由于其独特的分子识别性能、自组装性质和螺旋结构，DNA因此成为分子电子学领域的重要研究对象。如实验报道DNA及其衍生物的一系列新奇物理现象，包括手性诱导自旋选择效应、分子整流器和电荷分离器等。另一方面，近来多个实验成功制备多种二维硼烯结构，发现体系存在不同相硼烯所形成的线缺陷。本项目以DNA及其衍生物等低维体系为研究对象，利用理论建模和数值计算方法研究了上述体系的电荷、自旋输运以及拓扑性质。本项目主要研究内容包括：（1）DNA及其衍生物的电荷和自旋输运；（2）DNA-超导耦合体系与螺旋有机分子的拓扑性质；（3）石墨烯量子输运的杂质吸附效应；（4）线缺陷硼烯纳米带与双层硼烯纳米带的量子输运。通过本项目研究，所取得的主要成果包括：（1）构建了发夹DNA、四面体DNA、环形DNA等体系的量子输运模型，发现若干新奇物理现象，设计基于四面体DNA的电荷和自旋分离器，基于环形DNA的分子开关；发现DNA-超导耦合体系存在Majorana零模与拓扑量子相变；长程跃迁诱导单螺旋有机分子产生拓扑量子相变；杂质随机吸附在石墨烯纳米带的透射谱打开能隙，而杂质无序可增强其电荷输运性能；线缺陷硼烯纳米带存在共振隧穿现象。（2）在Physical Review B/Applied、npj Computational Materials等重要物理学期刊发表SCI论文14篇。（3）协助培养博士研究生1人次，培养硕士研究生3人次。概括而言，本项目发现了若干关于DNA、石墨烯、硼烯等体系的新奇物理现象，相应的研究成果为设计基于DNA的分子开关、自旋过滤器以及电荷和自旋分离器件提供理论基础和新途径，具有重要的科学指导意义。