N,B原子取代调控M-OPE分子器件的量子干涉与自旋输运  

Quantum interference and spin transport in M-OPE molecular devices controlled by N or B atom substitution

作　　者：彭淑平 邓淑玲 刘乾 董丞骐 范志强[1] Peng Shu-Ping;Deng Shu-Ling;Liu Qian;Dong Cheng-Qi;Fan Zhi-Qiang(School of Physics and Electronic Science,Changsha University of Science and Technology,Changsha 410114,China;College of Environmental Science and Engineering,Nanjing University of Technology,Nanjing 211816,China)

机构地区：[1]长沙理工大学物理与电子科学学院,长沙410114 [2]南京工业大学环境科学与工程学院,南京211816

出　　处：《物理学报》2024年第10期345-351,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12074046);湖南省研究生科研创新项目(批准号:CXCLY2022141)资助的课题。

摘　　要：采用第一性原理计算基础上结合非平衡格林函数方法,开展了N,B原子取代对间苯乙烯低聚物(M-OPE)分子器件量子干涉与自旋输运的调控研究.研究结果表明N,B原子在中心苯环不同位置取代对M-OPE分子器件原有的相消量子干涉抑制程度不同.因此,N,B原子在不同位置取代后的器件电导存在较大差异研究还发现B原子取代的器件自旋电流值要明显高于N原子取代的器件,且B原子在特定位置取代后,器件在负偏压下的自旋电流值要明显大于正偏压下的自旋电流值,呈现显著的自旋整流效应.本文得到的N,B原子取代对分子体系量子干涉和自旋输运调控的物理机制,可以为杂环芳烃在分子电子学中的进一步应用提供理论指导.In this paper,the first-principles method based on density functional theory and non-equilibrium Green’s function is used to investigate the modulation of quantum interference and spin transport in N and B atom substituted meta-phenylene(M-OPE)molecular devices.The zero bias spin transmission spectrum of M-OPE molecular device shows that highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)are located at higher energy positions on both sides of the Fermi level,and there is a clear transmission spectrum valley(anti resonance peak)on the right side of the Fermi level.This indicates that MOPE molecules are typical destructive quantum interference molecular systems.Research has found that N and B atoms replace carbon atoms at positions 1,2,and 3 on the central ring of the molecule,which suppress the original destructive quantum interference of M-OPE molecular device to different extents.The substitution of N and B atoms at position 1 has no effect on the original destructive quantum interference of M-OPE molecular device,while the substitution of N and B atoms at positions 2 and 3 significantly suppresses the original destructive quantum interference of M-OPE molecular device.Therefore,there is a significant difference in the electrical conductivity of devices with N and B atoms at different positions,with the order of electrical conductivity values being N2>N3>N1 and B2>B3>B1.In this study,it is also found that the spin current value of device with B atom substitution is significantly higher than that of device with N atom substitution.After the substitution of B atom at position 2,the spin current value of the device under negative bias is significantly greater than that under positive bias,exhibiting a significant spin rectification effect.Based on the extended curled arrow rule proposed by O’Driscoll et al.to predict the behavior of quantum interference effects,we explain the physical mechanism by which N and B protons at different positions have different effects on the suppre

关 键 词：第一性原理 密度泛函理论 分子器件 量子干涉 自旋输运 

分 类 号：O469[理学—凝聚态物理]