Effect of hydrogen molecules on the electronic transport through atomic-sized metallic junctions in the superconducting state
Effect of hydrogen molecules on the electronic transport through atomic-sized metallic junctions in the superconducting state
复制标题
氢分子对超导状态下原子大小金属结电子传输的影响
DOI：
10.1103/physrevb.78.045414
复制
发表时间：
2008
影响因子：
3.7
通讯作者：
A. Halbritter
中科院分区：
文献类型：
--
作者：
P. Makk;S. Csonka;A. Halbritter
本文研究了氢分子与原子级超导纳米结的相互作用。电导直方图测量表明，超导体铌、钽和铝与氢表现出强烈的相互作用，而对铅则观察到轻微的相互作用，而对锡和铟则没有明显的相互作用。对于Nb、Ta和Pb，应用子隙法测定了纳米结在氢环境下的透射特征值。结果表明，氢分子强烈地改变了Nb和Ta纳米结的行为，这体现在电导直方图的明显变化，电导痕迹的出现以及曲线上观察到的负差分电导现象。令人惊讶的是，基于测量传输特征值的输运性质与纯结的输运性质相似。结果表明，在Nb和Ta中，与氢的相互作用导致了塑性、延展性行为和长纳米级颈的形成，但没有形成明确的单分子接触，输运性质仍然由Nb和Ta主导。
In this paper the interaction of hydrogen molecules with atomic-sized superconducting nanojunctions is studied. It is demonstrated by conductance histogram measurements that the superconductors niobium, tantalum, and aluminum show a strong interaction with hydrogen, whereas for lead a slight interaction is observed and for tin and indium no significant interaction is detectable. For Nb, Ta, and Pb the subgap method is applied to determine the transmission eigenvalues of the nanojunctions in hydrogen environment. It is shown that the behavior of Nb and Ta nanojunctions is strongly modified by hydrogen molecules as reflected by the pronounced changes in the conductance histogram, the appearance of extremely long conductance traces, and the observation of negative differential conductance phenomenon in thecurve. Surprisingly the transport properties based on the measured transmission eigenvalues are similar to those of pure junctions. Our results imply that in Nb and Ta the interaction with hydrogen causes a plastic, ductile behavior and the formation of long nanoscale necks, but no well-defined single-molecule contacts are formed, and the transport properties are still dominated by Nb and Ta.