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arXiv 1003.1033cond-mat.supr-con
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单量子化超导涡旋相移的探测

Detection of the phase shift from a single quantized superconducting vortex

Taras Golod, Andreas Rydh, Vladimir M. Krasnov

摘要:

超导体中的Abrikosov涡旋携带一个定域在中心的通量量子Phi_0 = hc/2 e,但在超导凝聚体中引起全局的2 pi相位旋转。这种在磁场穿透区域之外的长程规范场是由于阿哈罗诺夫-玻姆效应,这是一种非经典现象,说明了量子力学中势而不是力的重要性。在伦敦规范中,凝聚态的相位由涡旋周围的极角给出。在这里,我们提出的问题,这种相移是否可以通过库珀对干涉测量使用约瑟夫森结作为相敏探测器检测。我们将一个单一的Abrikosov涡旋引入到超导导线中,在导线的边缘制作一个探测器结。我们观察到,涡流引起的约瑟夫森相移等于结长度内的涡流的极角。当涡旋靠近结时,它在约瑟夫森相位差中引起π阶跃,导致结可控且可逆地切换到0 -π状态。这反过来又导致结中通量的不寻常的Phi_0/2量子化。因此,涡旋可以作为量子电子学的可调谐“相位电池”。

英文摘要:

An Abrikosov vortex in a superconductor carries a flux quantum, Phi_0 = hc/2e, localized at its center, but induces a global 2pi phase rotation in the superconducting condensate. This long-range gauge field outside the area pierced by a magnetic field is due to the Aharonov-Bohm effect, which is a non-classical phenomenon that illustrates the significance of potentials rather than forces in quantum mechanics. In the London gauge, the phase of the condensate is given by the polar angle around the vortex. Here we raise the question whether this phase shift could be detected by means of Cooper pair interferometry using Josephson junctions as phase-sensitive detectors. We introduce a single Abrikosov vortex into a superconducting lead with a detector junction made at the edge of the lead. We observe that the vortex induces a Josephson phase shift equal to the polar angle of the vortex within the junction length. When the vortex is close to the junction it induces a pi-step in the Josephson phase difference, leading to a controllable and reversible switching of the junction into the 0 - pi state. This in turn results in an unusual Phi_0/2 quantization of the flux in the junction. The vortex may hence act as a tunable "phase battery" for quantum electronics.

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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