在小约瑟夫森十字路口展示双Shapiro步骤
Fabian Kaap1, Christoph Kissling2, Victor Gaydamachenko2
1Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116, Braunschweig, Germany. fabian.kaap@ptb.de.
Nature communications
|October 8, 2024
概括
研究人员在约瑟夫森连接处展示了布洛赫振荡,创造了量子化电流步骤. 这种量子二元效应为使用频率和基本电荷的电流测量提供了一个新的基本标准.
科学领域:
- 量子物理学的量子物理学
- 凝聚物质物理学 凝聚物质物理学
- 超导电性 超导电性 超导电性
背景情况:
- 布洛赫振荡在理论上被预测为小约瑟夫森交点中的约瑟夫森振荡的量子双.
- 这种双重性意味着在特定的同步条件下存在量子化电流步骤,称为双重Shapiro步骤.
研究的目的:
- 通过同步布洛赫振荡来实验实现电流 (I = ±n × 2ef) 的基本关系.
- 调查双 Shapiro 步骤的潜力,以建立一个基本的当前标准.
主要方法:
- 使用小型/氧化/ (Al/AlOx/Al) 约瑟夫森接口.
- 同步布洛克振荡与外部正弦微波驱动器,范围从1到6 GHz.
- 调查脉冲驱动模式以确认二元关系并观察步骤模式.
主要成果:
- 在约瑟夫森交叉点观察到双 Shapiro 步骤,直至大约 3 nA.
- 证实了由于同步的布洛赫振荡而产生量子化电流步骤的出现.
- 在脉冲驱动模式中观察到双Shapiro步骤的不对称模式,进一步验证了二元性.
结论:
- 这项研究通过实验证实了约瑟夫森交叉点中的量子二元效应.
- 这些发现为量子计量学的新应用铺平了道路,特别是用于电流标准.
- 使用已确定的制造技术和简单的电路设计有助于实际实施.
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