铜-真空-铜金属隧道结转变电压的理论研究

doi:10.3866/PKU.WHXB201506112

CORC > 北京大学 > 信息科学技术学院

	铜-真空-铜金属隧道结转变电压的理论研究; Theoretical Investigation of the Transition Voltages of Cu-Vacuum-Cu Tunneling Junctions
	白梅林 ; 王明郎 ; 侯士敏
刊名	物理化学学报
	2015
关键词	真空隧穿转变电压谱电子输运非平衡格林函数密度泛函理论 Vacuum tunneling Transition voltage spectroscopy Electron transport Non-equilibrium Green&apos Density functional theory MOLECULAR ELECTRONIC DEVICES TRANSPORT SPECTROSCOPY CONDUCTANCE WIRES s function
DOI	10.3866/PKU.WHXB201506112
英文摘要	利用非平衡格林函数与密度泛函理论相结合方法研究了电极表面具有原子级突起的铜-真空-铜隧道结的转变电压.计算结果表明,铜电极真空隧道结的转变电压主要决定于电极表面尖端铜原子4p轨道的局域态密度,因而对电极取向和表面局域原子构型非常敏感.对于电极取向沿(111)方向的铜电极真空隧道结,当电极表面原子级突起取为铜吸附原子和金字塔型铜纳米粒子两种构型时,转变电压的计算值分别约为1.40和2.40 V.当电极取向沿(100)方向时,电极表面原子级突起分别为铜吸附原子和金字塔型铜纳米粒子两种构型的铜电极真空隧道结,其转变电压的差异更为显著.具体而言,电极表面有一金字塔型铜纳米粒子的铜电极真空隧道结的转变电压值减小至1.70 V,而电极表面原子级突起为铜吸附原子的铜电极真空隧道结却因铜吸附原子4p轨道的局域态密度过于扩展,即使在偏压超过1.80 V时仍然没有出现转变电压.这些结果表明转变电压谱可用作分析金属电极真空隧道结电子输运特性的有力工具.; The transition voltage of copper-vacuum-copper tunneling junctions with atomic protrusions on the electrode surface was investigated using the non-equilibrium Green's function formalism combined with density functional theory. Our calculations show that the transition voltages of Cu-vacuum-Cu junctions with atomically sharp electrodes are mainly determined by the local density of state (LDOS) of the 4p atomic orbitals of the protrusion, and are thus sensitive to the electrode orientation and the variation of the atomic configurations of surface protrusions. For Cu-vacuum-Cu junctions with (111)-oriented electrodes, the transition voltages were calculated to be about 1.40 and 2.40 V when the atomic protrusions were chosen to be one Cu adatom or a copper cluster with four atoms arranged in a pyramid configuration, respectively. The transition voltages of Cu-vacuum-Cu junctions with (100)-oriented electrodes were more different. When the atomic protrusion on the Cu(100) surface was a copper cluster with five atoms arranged in a pyramid configuration, the transition voltage was 1.70 V. In contrast, no transition voltage was observed for Cu-vacuum-Cu junctions with one Cu adatom attached to the Cu(100) electrode surface even when the bias exceeded 1.80 V, which is caused by the LDOS of the 4p atomic orbitals of the Cu adatom on the Cu(100) surface being too extended. These results demonstrate the advantages of transition voltage spectroscopy as a tool for analyzing the electronic transport properties of metal-vacuum-metal tunneling junctions.; 国家自然科学基金,国家重点基础研究发展规划项目(973); SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); smhou@pku.edu.cn; 8; 1474-1482; 31
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/414336]
专题	信息科学技术学院
推荐引用方式 GB/T 7714	白梅林,王明郎,侯士敏. 铜-真空-铜金属隧道结转变电压的理论研究, Theoretical Investigation of the Transition Voltages of Cu-Vacuum-Cu Tunneling Junctions[J]. 物理化学学报,2015.
APA	白梅林,王明郎,&侯士敏.(2015).铜-真空-铜金属隧道结转变电压的理论研究.物理化学学报.
MLA	白梅林,et al."铜-真空-铜金属隧道结转变电压的理论研究".物理化学学报 (2015).