arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2402.02137cond-mat.mes-hall
收藏

磁场下微波辅助的Al-InAs纳米线-Al结中的单向超导性

Microwave-assisted unidirectional superconductivity in Al-InAs nanowire-Al junctions under magnetic fields

Haitian Su, Ji-Yin Wang, Han Gao, Yi Luo, Shili Yan, Xingjun Wu, Guoan Li, Jie Shen, Li Lu, Dong Pan, Jianhua Zhao, Po Zhang, H. Q. Xu

AI总结:

本文实验研究了微波驱动和磁场下Al-InAs纳米线-Al约瑟夫森结的超导二极管效应,发现微波可增强该效应并实现单向超导性,且偏移幅度对微波功率近似线性响应,但RSJ模型无法完全解释,提示存在新的非平衡机制。

摘要:

在某些对称性破缺条件下,超导系统会表现出不对称的临界电流,被称为“超导二极管效应”。近年来,具有理想超导二极管效率或单向超导性的系统引起了广泛关注。在本工作中,我们报道了在微波辐照和磁场作用下对Al-InAs纳米线-Al约瑟夫森结的研究。我们观察到在微波驱动下超导二极管效应的增强,其特征是电压-电流特性中零电压台阶的水平偏移随微波功率增大而增大。在足够高的驱动幅度下,器件达到单向超导性区域。该偏移随磁场方向反转而改变符号。同时,当功率和磁场都较大时,偏移幅度对以dBm为单位的微波功率表现出近似线性的响应。所观察到的特征让人联想到最近一项使用电阻分流结(RSJ)模型的理论提议。然而,实验结果并不能完全由RSJ模型解释,这表明存在一种新的单向超导性机制,可能与周期性驱动超导系统中的非平衡动力学或耗散有关。

英文摘要:

Under certain symmetry-breaking conditions, a superconducting system exhibits asymmetric critical currents, dubbed the ``superconducting diode effect". Recently, systems with the ideal superconducting diode efficiency or unidirectional superconductivity have received considerable interest. In this work, we report the study of Al-InAs nanowire-Al Josephson junctions under microwave irradiation and magnetic fields. We observe an enhancement of superconducting diode effect under microwave driving, featured by a horizontal offset of the zero-voltage step in the voltage-current characteristic that increases with microwave power. Devices reach the unidirectional superconductivity regime at sufficiently high driving amplitudes. The offset changes sign with the reversal of the magnetic field direction. Meanwhile, the offset magnitude exhibits a roughly linear response to the microwave power in dBm when both the power and the magnetic field are large. The signatures observed are reminiscent of a recent theoretical proposal using the resistively shunted junction (RSJ) model. However, the experimental results are not fully explained by the RSJ model, indicating a new mechanism for unidirectional superconductivity that is possibly related to non-equilibrium dynamics or dissipation in periodically driven superconducting systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑