论文标题
两分量玻色 - 因斯坦冷凝物中相位相干性的基本极限
Fundamental limit of phase coherence in two-component Bose-Einstein condensates
论文作者
论文摘要
我们在Atom芯片上的$^{87} {\ rm rb} $原子的两个组分玻色 - 因斯坦冷凝物中进行实验和理论上研究阶段相干性。使用Ramsey干涉法，我们测量了$ | f = 1，m_ {f} = - 1 \ rangle $和$ | f = 2，m_ {f} =+1 \ rangle $ hyperfine地基态之间的相干性衰减。我们观察到，由于原子损失的随机性质，相干性受到随机碰撞相移的限制。该机制通过基于主方程的量子轨迹方法定量确认，该方法考虑了碰撞相互作用，原子数波动和系统中的损失。通过降低冷凝物的密度，可以减慢这种破裂过程。我们的发现与与Bose-Einstein冷凝物的量子计量学和许多粒子纠缠的实验有关，以及基于芯片的原子钟的发展。
We experimentally and theoretically study phase coherence in two-component Bose-Einstein condensates of $^{87}{\rm Rb}$ atoms on an atom chip. Using Ramsey interferometry we measure the temporal decay of coherence between the $|F=1,m_{F}=-1\rangle$ and $|F=2,m_{F}=+1\rangle$ hyperfine ground states. We observe that the coherence is limited by random collisional phase shifts due to the stochastic nature of atom loss. The mechanism is confirmed quantitatively by a quantum trajectory method based on a master equation which takes into account collisional interactions, atom number fluctuations, and losses in the system. This decoherence process can be slowed down by reducing the density of the condensate. Our findings are relevant for experiments on quantum metrology and many-particle entanglement with Bose-Einstein condensates and the development of chip-based atomic clocks.
