论文标题
对线宽的连续波激光器的提案，远低于标准量子极限
Proposal for a continuous wave laser with linewidth well below the standard quantum limit
论文作者
论文摘要
由于它们的高连贯性，激光是科学中普遍存在的工具。我们表明，通过工程化增益介质和激光腔之间以及激光腔和输出端口之间的耦合，可以消除由于进入激光腔并离开激光腔而引起的大部分噪声。因此，有可能将激光线宽降低等于低于标准量子极限的激光腔中的光子数量。我们设计和理论上分析了使用约瑟夫森连接，电容器和电感器实现微波激光器的超导电路，包括允许设计超过标准量子限制的低噪声耦合器。我们的建议依赖于超导量子信息的要素，因此是量子工程技术如何激发我们重新想象常规量子系统极限的一个例子。
Due to their high coherence, a laser is a ubiquitous tool in science. We show that by engineering the coupling between the gain medium and the laser cavity as well as the laser cavity and the output port, it is possible to eliminate most of the noise due to photons entering as well as leaving the laser cavity. Hence, it is possible to reduce the laser linewidth by a factor equal to the number of photons in the laser cavity below the standard quantum limit. We design and theoretically analyze a superconducting circuit that uses Josephson junctions, capacitors and inductors to implement a microwave laser, including the low-noise couplers that allow the design to surpass the standard quantum limit. Our proposal relies on the elements of superconducting quantum information, and thus is an example of how quantum engineering techniques can inspire us to re-imagine the limits of conventional quantum systems.
