Quantum switch in the gravity of Earth

地球引力作用下量子超冷中子气体的热力学

Thermodynamics of Quantum Ultra-cold Neutron Gas under Gravity of The Earth

研制了贮存的超冷中子。用核聚变方法制备了高密度超冷中子气体。研究了量子超冷中子气体在地球引力场中的热力学性质。我们发现，在低温区，量子效应增加了化学势和内能的温度依赖性。量子超冷中子气体的密度分布受地球引力场的影响。

量子力学与引力界面中的不定序

Indefinite order in the interface of quantum mechanics and gravity

本硕士论文探讨量子力学与引力界面中的不定序概念，介绍量子开关等典型案例，提出经典史瓦西度规下的量子开关构想，为弯曲时空量子力学实验检验提供新方案。

A Gravity of Earth Measurement with a qBOUNCE Experiment

We report a measurement of the local acceleration $g$ with ultracold neutrons based on quantum states in the gravity potential of the Earth. The new method uses resonant transitions between the states $|1> -> |3>$ and for the first time between $|1> -> |4>$. The measurements demonstrate that Newton's Inverse Square Law of Gravity is understood at micron distances at an energy level of $10^{-14}$ eV with $\frac{Δg}{g}=4\times10^{-3}$. The results provide constraints on any possible gravity-like interaction at a micrometer interaction range. In particular, a dark energy candidate, the chameleon …

Measuring the Earth's gravity field with cold atom interferometers

The scope of the paper is to propose different concepts for future space gravity missions using Cold Atom Interferometers (CAI) for measuring the diagonal elements of the gravity gradient tensor, the spacecraft angular velocity and the spacecraft acceleration. The aim is to achieve better performance than previous space gravity missions due to a very low white noise spectral behaviour of the CAI instrument and a very high common mode rejection, with the ultimate goals of determining the fine structures of the gravity field with higher accuracy than GOCE and detecting time-variable signals in t…

地球引力中中子的量子化

Quantization of neutron in Earth's gravity

引力是宇宙中已知的四种力中最弱的一种。由于这样一个弱场，基本粒子的量子态肯定是非常浅的，因此将是一个实验上的挑战。最近，V. V. Nesvizhevsky等人进行了一项实验尝试，Nature 415，297（2002），以测量中子的量子态，其显示基态和少数激发态为\sim 10^{-12}eV。我们证明了限制在地球表面以上的中子的基态能量应为\sim 10^{-37}eV。实验观察到的能级比实际的能级深10^{25}倍，因此肯定不是由于地球的引力效应。因此，对参考文献\cite{nes1}的艰苦实验结果的正确解释是由于长度为L \sim 50μm的一维盒子的限制势，该限制势是由\cite{hansoon}之前评论的实验装置产生的。我们的结果对今后解决地球引力场中中子的浅能级问题提出了新的挑战。

Gravity enhanced quantum spatial target detection

Quantum illumination can utilize entangled light to detect the low-reflectivity target that is hidden in a bright thermal background. This technique is applied to the detection of an object in the curved spacetime of the Earth, in order to explore how the curvature of spacetime affects quantum illumination. It is found that the spatial quantum illumination with entangled state transmitter outperforms that with coherent-state transmitter in the near-Earth curved spacetime. Moreover, either the quantum illumination system or the coherent-state system is employed, and gravity can enhance the spac…