Cragg George E, Kerman Arthur K
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Phys Rev Lett. 2007 Feb 23;98(8):080405. doi: 10.1103/PhysRevLett.98.080405. Epub 2007 Feb 22.
Atomic Bose-Einstein condensates are singular forms of matter with the coherence between constituent atoms as a defining characteristic. Although this viewpoint is increasingly validated through experimental findings, the mechanisms behind the observed losses are still understood with classical recombinant collision arguments between particles within the condensate itself. By incorporating a general interparticle interaction into the Hamiltonian, a coherent decay rate can be obtained, thus providing a direct link between the observed losses and the microscopic two-body parameters. Appearing in the lifetime, the interaction strength, lambda, is expressed as lambda=8 pia/(1-delta), where the small parameter delta is obtained from a fit to experimental loss data. Most importantly, the lowest order rate exhibits a novel density dependence (rho{3/2}) that can be identified in low temperature tests.
原子玻色 - 爱因斯坦凝聚体是物质的奇异形式，其构成原子之间的相干性是一个决定性特征。尽管这一观点越来越多地通过实验结果得到验证，但观察到的损失背后的机制仍通过凝聚体本身内粒子间的经典复合碰撞论据来理解。通过将一般的粒子间相互作用纳入哈密顿量，可以得到一个相干衰减率，从而在观察到的损失与微观两体参数之间建立直接联系。出现在寿命中的相互作用强度λ表示为λ = 8πa/(1 - δ)，其中小参数δ通过对实验损失数据的拟合得到。最重要的是，最低阶速率呈现出一种新的密度依赖性（ρ^{3/2}），这在低温测试中可以识别。
