Quantized conductance through individual rows of suspended gold atoms
Quantized conductance through individual rows of suspended gold atoms
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DOI：
10.1038/27399
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发表时间：
1998-10-22
期刊：
影响因子：
64.8
通讯作者：
Takayanagi, K
中科院分区：
文献类型：
--
作者：
Ohnishi, H;Kondo, Y;Takayanagi, K
随着微电子工程的规模不断缩小，人们的兴趣集中在电子通过基本上一维纳米尺度通道（如量子线（1）和碳纳米管（2，3））传输的性质上。量子点接触（QPC）是一种结构（通常是金属），其中原子的“颈部”只有几个原子直径宽（即与传导电子的费米波长相当）桥接两个电接触。它们可以通过将金属表面与扫描隧道显微镜（STM）接触（4-7）和通过其他方法（8-12）来制备，并且通常显示以2 e（2）/h（类似于13 k Ω（-1））（13，14）的步长量化的电导，其中e是电子电荷，h是普朗克常数。在这里，我们报告了用STM制备的金属QPC的电导测量，我们可以同时使用超高真空电子显微镜成像，这允许直接观察电子传输和结构之间的关系，我们观察到大约一纳米长的金原子链和一个单链的金原子悬浮在电极之间。因此，我们可以证实，单链原子的电导是2 e（2）/h，双链原子的电导是2 e（2）/h的两倍，这表明在这些量子系统中电子输运遵循均分原理。
As the scale of microelectronic engineering continues to shrink, interest has focused on the nature of electron transport through essentially one-dimensional nanometre-scale channels such as quantum wires(1) and carbon nanotubes(2,3). Quantum point contacts (QPCs) are structures (generally metallic) in which a 'neck' of atoms just a few atomic diameters wide (that is, comparable to the conduction electrons' Fermi wavelength) bridges two electrical contacts. They can be prepared by contacting a metal surface with a scanning tunnelling microscope (STM)(4-7) and by other methods(8-12) and typically display a conductance quantized in steps of 2e(2)/h(similar to 13 k Omega(-1))(13,14), where e is the electron charge and h is Planck's constant. Here we report conductance measurements on metal QPCs prepared with an STM that we can simultaneously image using an ultrahigh-vacuum electron microscope, which allows direct observation of the relation between electron transport and structure, We observe strands of gold atoms that are about one nanometre long and one single chain of gold atoms suspended between the electrodes. We can thus verify that the conductance of a single strand of atoms is 2e(2)/h and that the conductance of a double strand is twice as large, showing that equipartition holds for electron transport in these quantum systems.