量子化电流步骤是由于微波与小约瑟夫森连接处的布洛赫振荡同步发生的
Rais S Shaikhaidarov1,2, Kyung Ho Kim1, Jacob Dunstan1
1Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK.
Nature communications
|October 30, 2024
概括
我们通过将布洛赫振荡与微波同步来证明约瑟夫森连接 (JJs) 中的电流量化,这是沙皮罗步骤的双重效应. 这一发现对于制定当前的计量标准至关重要.
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
背景情况:
- 在微波辐射下的约瑟夫森结 (JJs) 中布洛赫振荡的同步理论上是与沙皮罗步骤的双重.
- 这种现象导致了当前量子化,这是为当前的计量标准提出的.
- 之前的电流量子化演示是在超导纳米线上.
研究的目的:
- 在微波辐射下在JJ中演示和研究当前量子化.
- 探索观察这种效应的条件和局限性.
- 了解热噪声在电流量化中的作用.
主要方法:
- 将JJ置于具有高阻抗的环境中.
- 使用高达24 GHz的微波辐射.
- 使用热噪声的JJ模型进行系统研究.
主要成果:
- 在JJs中展示了双 Shapiro 步骤,当前量子化高达24 GHz (I = 7.7 nA).
- 只有在一个狭窄的JJ参数范围内观察到电流量化.
- 通过将热噪声纳入JJ模型来解释参数依赖.
结论:
- 在JJs中通过同步的布洛赫振荡确认了电流量化.
- 识别的参数灵敏度和热噪声的影响.
- 这些发现对基础物理学和量子计量学应用具有重要意义.
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