Li Wei, Tuchman Ari K, Chien Hui-Chun, Kasevich Mark A
Physics Department, Stanford University, Stanford, California 94305, USA.
Phys Rev Lett. 2007 Jan 26;98(4):040402. doi: 10.1103/PhysRevLett.98.040402. Epub 2007 Jan 23.
Coherence properties of Bose-Einstein condensates offer the potential for improved interferometric phase contrast. However, decoherence effects due to the mean-field interaction shorten the coherence time, thus limiting potential sensitivity. In this work, we demonstrate increased coherence times with number squeezed states in an optical lattice using the decay of Bloch oscillations to probe the coherence time. We extend coherence times by a factor of 2 over those expected with coherent state Bose-Einstein condensate interferometry. We observe quantitative agreement with theory both for the degree of initial number squeezing as well as for prolonged coherence times.
玻色-爱因斯坦凝聚体的相干特性为提高干涉相衬度提供了潜力。然而，由于平均场相互作用导致的退相干效应缩短了相干时间，从而限制了潜在的灵敏度。在这项工作中，我们利用布洛赫振荡的衰减来探测相干时间，在光学晶格中使用数压缩态展示了更长的相干时间。我们将相干时间延长至相干态玻色-爱因斯坦凝聚体干涉测量预期值的两倍。我们观察到，无论是初始数压缩程度还是延长的相干时间，都与理论定量相符。
