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arXiv 2101.07063cond-mat.supr-con
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窄约瑟夫森结中的持续电流噪声

Persistent current noise in narrow Josephson junctions

Dushko Kuzmanovski, Rubén Seoane Souto, Alexander V. Balatsky

摘要:

约瑟夫森结在计量学、量子信息处理和遥感中具有广泛的应用。对于这些应用,电子噪声是一个限制因素。本文利用紧束缚哈密顿量研究了窄约瑟夫森结中的热噪声。对于长于超导相干长度的结,几个自洽的间隙轮廓出现接近相位差$π$。它们对应于由$2π$相位滑移和孤子分支连接的薄超导体上具有近似恒定相位梯度的两个稳定解。电流噪声功率谱在每个分支中的不同状态之间的过渡频率处具有明显的峰值。我们发现,噪声是减少在梯度分支相比,零长度的交界处的限制。相反,由于最低激发能被钉扎到接近于零的能量,孤子分支表现出增强的噪声和减小的电流。

英文摘要:

Josephson junctions have broad applications in metrology, quantum information processing, and remote sensing. For these applications, the electronic noise is a limiting factor. In this work we study the thermal noise in narrow Josephson junctions using a tight-binding Hamiltonian. For a junction longer than the superconducting coherence length, several self-consistent gap profiles appear close to a phase difference $π$. They correspond to two stable solutions with an approximately constant phase gradient over the thin superconductor connected by a $2π$ phase slip, and a solitonic branch. The current noise power spectrum has pronounced peaks at the transition frequencies between the different states in each branch. We find that the noise is reduced in the gradient branches in comparison to the zero-length junction limit. In contrast, the solitonic branch exhibits an enhanced noise and a reduced current due to the pinning of the lowest excitation energy to close to zero energy.

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。

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