论文标题
微波诱导的电导复制品在没有Floquet Andreev状态的混合动力Josephson连接处
Microwave-induced conductance replicas in hybrid Josephson junctions without Floquet-Andreev states
论文作者
论文摘要
轻度 - 互动使非平衡量子系统的工程。在凝结物质中，预计在空间和时间上循环的汉密尔顿人会产生能量周期性的浮雕状态，并且在热平衡处的性质无法访问。最近的一项工作探讨了在微波辐射下的平面约瑟夫森交界处的隧道电导，并将电导功能的复制品解释为稳定的浮雕和弗拉奎夫州的证据。在这里，我们在混合超导 - 通导异质结构中实现了类似的装置，该异质结构使用了具有栅极可调透明度的隧道探测器，并允许同时测量Andreev Spectrum spectrum spectrum and Current-phase phass phass phass phass phass spase splan of the Planar Josephson Junction。我们表明，在我们的设备中，在微波辐照下出现的亚隙电导中的光谱复制品是由电子辅助隧穿到Andreev态引起的。微波辐照下的电流相关关系也通过Andreev状态与微波光子的相互作用来解释，而无需调用Floquet状态。这项研究中概述的技术建立了一个基线，可以将光子辅助的隧道与介质设备中的floquet Andreev状态区分开，这是理解混合纳米结构中光结合的关键发展。
Light-matter interaction enables engineering of non-equilibrium quantum systems. In condensed matter, spatially and temporally cyclic Hamiltonians are expected to generate energy-periodic Floquet states, with properties inaccessible at thermal equilibrium. A recent work explored the tunnelling conductance of a planar Josephson junction under microwave irradiation, and interpreted replicas of conductance features as evidence of steady Floquet-Andreev states. Here we realise a similar device in a hybrid superconducting-semiconducting heterostructure, which utilises a tunnelling probe with gate-tunable transparency and allows simultaneous measurements of Andreev spectrum and current-phase relation of the planar Josephson junction. We show that, in our devices, spectral replicas in sub-gap conductance emerging under microwave irradiation are caused by photon assisted tunnelling of electrons into Andreev states. The current-phase relation under microwave irradiation is also explained by the interaction of Andreev states with microwave photons, without the need to invoke Floquet states. The techniques outlined in this study establish a baseline to distinguish photon assisted tunnelling from Floquet-Andreev states in mesoscopic devices, a crucial development towards understanding light-matter coupling in hybrid nanostructures.
