Superconductivity-enhanced bias spectroscopy in carbon nanotube quantum dots
Superconductivity-enhanced bias spectroscopy in carbon nanotube quantum dots
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DOI：
10.1103/physrevb.79.134518
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发表时间：
2009-04-01
影响因子：
3.7
通讯作者：
Lindelof, P. E.
中科院分区：
文献类型：
--
作者：
Grove-Rasmussen, K.;Jorgensen, H. I.;Lindelof, P. E.
我们研究了低温下通过碳纳米管量子点耦合到超导铅的库仑阻塞制度。我们观察到明显的电导峰在有限的源漏偏置，我们归因于弹性和非弹性cotunneling过程增强的超导导线的状态密度的相干峰。非弹性共隧穿阈值显示了显着的依赖于栅极电压所造成的不同的隧道重整化的两个子带的纳米管。最后，我们讨论了在奇电子占据的强耦合器件中观察到的依赖于栅极的亚带隙结构。
We study low-temperature transport through carbon nanotube quantum dots in the Coulomb blockade regime coupled to niobium-based superconducting leads. We observe pronounced conductance peaks at finite source-drain bias, which we ascribe to elastic and inelastic cotunneling processes enhanced by the coherence peaks in the density of states of the superconducting leads. The inelastic cotunneling thresholds display a marked dependence on gate voltage caused by different tunneling renormalizations of the two subbands in the nanotube. Finally, we discuss the gate-dependent subgap structure observed in a strongly coupled device with odd electron occupation.