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arXiv 2302.14535cond-mat.mes-hallcond-mat.supr-con
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对三端 Josephson 结 Andreev 能带结构的相位工程调控

Phase-engineering the Andreev band structure of a three-terminal Josephson junction

M. Coraiola, D. Z. Haxell, D. Sabonis, H. Weisbrich, A. E. Svetogorov, M. Hinderling, S. C. ten Kate, E. Cheah, F. Krizek, R. Schott, W. Wegscheider, J. C. Cuev… 展开作者

M. Coraiola, D. Z. Haxell, D. Sabonis, H. Weisbrich, A. E. Svetogorov, M. Hinderling, S. C. ten Kate, E. Cheah, F. Krizek, R. Schott, W. Wegscheider, J. C. Cuevas, W. Belzig, F. Nichele

AI总结:

该研究通过 InAs/Al 三端 Josephson 结的双环相位控制,实验观测到二维相位空间中 Andreev 能级杂化形成的 Andreev 分子及其避免交叉和各向异性。

摘要:

在具有三个或更多超导端并与半导体区域耦合的混合 Josephson 结中,Andreev 束缚态可能形成非传统的能带结构,即 Andreev 物质,并可通过控制超导相位差来进行工程调控。这里,我们报道了在 InAs/Al 异质结构中实现的三端 Josephson 结的隧穿谱测量。三个端子连接形成两个环路,从而能够独立控制两个相位差,并在二维相位空间中访问合成的 Andreev 能带结构。我们的结果展示了一个受相位控制的 Andreev 分子,它源于两个在空间上重叠并杂化的离散 Andreev 能级。杂化的特征以谱中的避免交叉和相位空间中的能带结构各向异性的形式被观测到,所有这些都可由一个数值模型解释。本工作未来的扩展可聚焦于在多端几何结构中处理自旋分辨能级、基态费米子宇称跃迁以及 Weyl 能带。

英文摘要:

In hybrid Josephson junctions with three or more superconducting terminals coupled to a semiconducting region, Andreev bound states may form unconventional energy band structures, or Andreev matter, which are engineered by controlling superconducting phase differences. Here we report tunnelling spectroscopy measurements of three-terminal Josephson junctions realised in an InAs/Al heterostructure. The three terminals are connected to form two loops, enabling independent control over two phase differences and access to a synthetic Andreev band structure in the two-dimensional phase space. Our results demonstrate a phase-controlled Andreev molecule, originating from two discrete Andreev levels that spatially overlap and hybridise. Signatures of hybridisation are observed in the form of avoided crossings in the spectrum and band structure anisotropies in the phase space, all explained by a numerical model. Future extensions of this work could focus on addressing spin-resolved energy levels, ground state fermion parity transitions and Weyl bands in multiterminal geometries.

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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