Here at the Lab for Quantum Measurement and Communication (QMC). We are doing researches on the generation and preparation of nonclassical optical fields and their applications to quantum measurement, quantum information, and so on.
We have finished some research projects, such as “absorption measurement beyond the shot noise limit”, “the generation and application of frequency-detuned nonclassical light”, “experimental research of quantum teleportation”, “continuous-wave quantum state transferring and quantum cloning” and “multi-color and multi-partite entanglement in the cascade nonlinear processes”. We are currently doing researches on the generations of spatial and temporal multimode nonclassical states and quantum precision measurements: the generation of cw hyperentanglement state, the generation of spatial squeezing and entanglement, precision measurement of spatial small displacement, tilt, orbital angular momentum and small rotation angle, experimental demonstration of wave-particle duality and uncertainty principle.
To learn more about an individual research, follow the links in the navigation bar.
Experimental Generation of Continuous-Variable Hyperentanglement in an Optical Parametric Oscillator
Authors：Kui Liu, Jun Guo, Chunxiao Cai, Shuaifeng Guo, and Jiangrui Gao
我们报道了在单个二类光学参量振荡器中同时具有偏振与轨道角动量纠缠的连续变量超纠缠态光场。通过补偿空间模式的像散，我们产生了一对厄米高斯模纠缠光束。通过关联测量，通过常用的纠缠判据我们证明了产生了连续变量超纠缠态光场。
Generation of a continuous-variable quadripartite cluster state multiplexed in the spatial domain
Authors：Chunxiao Cai, Long Ma, Juan Li, Hui Guo, Kui Liu, Hengxin Sun, Rongguo Yang, Jiangrui Gao
在高度纠缠网络当中，cluster态在更大的信息容量和基于测量的量子计算当中具有潜在应用价值。这里我们报道了在单个光学参量振荡器中产生连续变量四组份空间正交模式cluster态，并且通过优化泵浦模式进一步提高了纠缠质量。与基模泵浦进行对比，使用最佳泵浦模式增强了33%。我们的方法可以拓展到空间领域当中。这种空间四组份cluster态有望应用于未来的空间量子信息处理的方案。
Squeezing-enhanced rotating-angle measurement beyond the quantum limit
Authors：Kui Liu, Chunxiao Cai, Juan Li, Long Ma, Hengxin Sun, and Jiangrui Gao
利用量子光源，量子计量可以提高测量精度。这里我们介绍一种提高转角测量的方案。通过理论证明，借助一种量子态我们叫它轨道角动量位置压缩态和平衡零拍探测。我们实验上证明了超越标准量子极限3dB的转角测量。接下来我们讨论了，进一步提高测量精度需要更高阶的轨道角动量位置压缩光。该方法有望在未来的实际当中应用，比如高灵敏的赛格尼克干涉仪。
Small-displacement measurements using high-order Hermite-Gauss modes
Authors：Hengxin Sun, Kui Liu, Zunlong Liu, Pengliang Guo, Junxiang Zhang and Jiangrui Gao
