Heralded noiseless linear amplification and distillation of entanglement
Heralded noiseless linear amplification and distillation of entanglement
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DOI：
10.1038/nphoton.2010.35
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发表时间：
2009-07
期刊：
影响因子：
35
通讯作者：
G. Xiang;T. Ralph;A. Lund;A. Lund;N. Walk;G. Pryde
中科院分区：
文献类型：
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作者：
G. Xiang;T. Ralph;A. Lund;A. Lund;N. Walk;G. Pryde
在物理系统的控制中，信号放大是无处不在的，而放大器的最终性能极限是由量子物理设定的。增加未知量子光场的振幅，或任何谐振子状态，必然会引入噪声。这种线性放大噪声阻止了量子态的完美复制，对通信和计量学施加了量子限制，并且是通过局域操作防止纠缠增加的机制。理想克隆和局域纠缠增加(蒸馏)的非确定性版本是允许的，这暗示了非确定性无声线性放大的可能性。在这里，我们介绍并实验演示了这样一种用于光场量子态的无噪声线性放大器，并将其用于场模纠缠的蒸馏。这种简单但强大的电路使增强量子技术的实用设备成为可能。无声放大的想法将克隆和蒸馏的方法统一起来，并将在量子计量学和通信中得到应用。
Signal amplification is ubiquitous in the control of physical systems, and the ultimate performance limit of amplifiers is set by quantum physics. Increasing the amplitude of an unknown quantum optical field, or any harmonic oscillator state, must introduce noise. This linear amplification noise prevents perfect copying of the quantum state, enforces quantum limits on communications and metrology, and is the mechanism preventing the increase of entanglement via local operations. Non-deterministic versions of ideal cloning and local entanglement increase (distillation) are allowed, suggesting the possibility of non-deterministic noiseless linear amplification. Here we introduce, and experimentally demonstrate, such a noiseless linear amplifier for quantum states of the optical field, and use it for distillation of field-mode entanglement. This simple but powerful circuit enables practical devices for enhancing quantum technologies. The idea of noiseless amplification unifies approaches to cloning and distillation, and will find applications in quantum metrology and communications.