Gate-tunable negative differential conductance in hybrid semiconductor-superconductor devices
| Autor: | Liu, Mingli, Pan, Dong, Le, Tian, He, Jiangbo, Jia, Zhongmou, Zhu, Shang, Yang, Guang, Lyu, Zhaozheng, Liu, Guangtong, Shen, Jie, Zhao, Jianhua, Lu, Li, Qu, Fanming |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Chin. Phys. Lett. 40 067301 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0256-307X/40/6/067301 |
| Popis: | Negative differential conductance (NDC) manifests as a significant characteristic of various underlying physics and transport processes in hybrid superconducting devices. In this work, we report the observation of gate-tunable NDC outside the superconducting energy gap on two types of hybrid semiconductor-superconductor devices, i.e., normal metal-superconducting nanowire-normal metal and normal metal-superconducting nanowire-superconductor devices. Specifically, we study the dependence of the NDCs on back-gate voltage and magnetic field. When the back-gate voltage decreases, these NDCs weaken and evolve into positive differential conductance dips; and meanwhile they move away from the superconducting gap towards high bias voltage, and disappear eventually. In addition, with the increase of magnetic field, the NDCs/dips follow the evolution of the superconducting gap, and disappear when the gap closes. We interpret these observations and reach a good agreement by combining the Blonder-Tinkham-Klapwijk (BTK) model and the critical supercurrent effect in the nanowire, which we call the BTK-supercurrent model. Our results provide an in-depth understanding of the tunneling transport in hybrid semiconductor-superconductor devices. Comment: 15+6 pages, 4+6 figures |
| Databáze: | arXiv |
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