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用约瑟夫森环调制器在量子极限附近进行相位保护放大
N Bergeal1, F Schackert, M Metcalfe
1Department of Physics and Applied Physics, Yale University, New Haven, Connecticut 06520-8284, USA. nicolas.bergeal@espci.fr
Nature
|May 7, 2010
概括
研究人员开发了一种新的超导参数放大器,可以保存相位信息,这对于量子信息处理至关重要. 这种相守放大器实现了接近量子限制的噪声性能,为量子技术开辟了新的途径.
科学领域:
- 量子信息处理 量子信息处理
- 超导装置的超导器件
- 微波放大器 微波放大器
背景情况:
- 固态量子信息处理需要量子有限的放大器和频率转换器.
- 线性放大器被分为相位敏感或相位保存,具有不同的噪声特性.
- 阶段保存放大器是非常理想的,但一直没有可用.
研究的目的:
- 实验实现一个内在的相位保护超导参数放大器.
- 为了演示一个具有量子有限性能的设备,用于微波信号.
- 为了实现量子模拟信号处理中的新应用.
主要方法:
- 使用一个约瑟夫森环调节器与四个约瑟夫森连接处在一个Wheatstone桥的配置.
- 实现了一个非退化的参数放大方案.
- 通过使用一种新的噪声源来描述放大器的增益,带宽和噪声特性.
主要成果:
- 成功实现了维护相位的超导参数放大器.
- 实现了与分析预测一致的增益和带宽特征.
- 在运行条件下,总系统噪声的上限是量子极限的三倍.
结论:
- 开发的约瑟夫森环调节器放大器本质上是维护相位的.
- 该设备为量子模拟信号处理应用提供了重大进步.
- 潜在的应用包括量子非拆除读数,量子反和纠的微波对生成.
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