On-chip sensing of hotspots in superconducting terahertz emitters.
On-chip sensing of hotspots in superconducting terahertz emitters.
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DOI：
10.1021/acs.nanolett.0c00551
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发表时间：
2020-01
期刊：
影响因子：
10.8
通讯作者：
Xianjing Zhou;Xu Han;D. Koelle;R. Kleiner;U. Welp;Xufeng Zhang;D. Jin
中科院分区：
文献类型：
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作者：
Xianjing Zhou;Xu Han;D. Koelle;R. Kleiner;U. Welp;Xufeng Zhang;D. Jin
高温超导体Bi2Sr2CaCu2O8中的本征约瑟夫森结以其发射具有广泛可调谐频率的高功率太赫兹光子的能力而闻名。热点作为跨结的非均匀温度分布，被认为在同步结之间的规范不变相位差，从而实现相干强发射方面起着关键作用。在本文中，我们展示了一种片上原位传感技术，可以精确地表征BSCCO的热点配置文件。这是通过在“发射极”结的顶部制造一系列微纳米尺寸的“传感器”结并测量传感器上的临界电流与施加到发射极的偏置电流来实现的。这种完全电子化的片上设计可以实现对BSCCO结中热点的有效闭环控制，并显着增强超导太赫兹发射器的功能。
Intrinsic Josephson junctions in high-temperature superconductor Bi2Sr2CaCu2O8 are known for their capability to emit high-power terahertz photons with widely tunable frequencies. Hotspots, as inhomogeneous temperature distributions across the junctions, are believed to play a critical role in synchronizing the gauge-invariant phase difference among the junctions, so as to achieve coherent strong emission. In this paper, we demonstrate an on-chip in situ sensing technique that can precisely characterize the hotspot profiles on BSCCO. This is achieved by fabricating a series of micro-nano-sized "sensor" junctions on top of an "emitter" junction and measuring the critical current on the sensors versus the bias current applied to the emitter. This fully electronic on-chip design can enable efficient close-loop control of hotspots in BSCCO junctions and significantly enhance the functionality of superconducting terahertz emitters.