论文标题
通过量子衍射通用性测量RB-RB范德华系数
Measurement of Rb-Rb van der Waals coefficient via Quantum Diffractive Universality
论文作者
论文摘要
被困原子或室温颗粒的被困原子之间的碰撞在周围真空中以与背景气体颗粒密度成正比的速率诱导被困种群的损失。用于此类碰撞的总速度平均损耗系数$ \ langleσ_\ mathrm {tot} v \ rangle $以及陷阱深度的损耗率的变化仅取决于碰撞伙伴之间的远距离交互潜力。这种碰撞普遍性先前用于实现自校准，基于原子的一级压力标准，并通过与孔口流量标准进行间接比较来验证。在这里，我们使用碰撞普遍性来测量$ \ langleσ_\ Mathrm {tot} v \ rangle = 6.44（11）（5）（5）\ times 10^{ - 15}〜\ rm {m^3/s} $ rb-rb的rb-rb碰撞，并根据相应的$ c_6 = 4688（1988888888888（95）〜E_______________________________________hha（95）〜e_e_e_e_e_e_e_e_e_e_e__e_e_e_e_e_e_ er yha（95） $ \ textit {ab initio} $计算并先前测量的$ C_6 $值。
Collisions between trapped atoms or trapped molecules with room temperature particles in the surrounding vacuum induce loss of the trapped population at a rate proportional to the density of the background gas particles. The total velocity-averaged loss rate coefficient $\langle σ_\mathrm{tot} v \rangle$ for such collisions and the variation of the loss rate with trap depth has been shown to depend only on the long range interaction potential between the collision partners. This collision universality was previously used to realize a self-calibrating, atom-based, primary pressure standard and was validated by indirect comparison with an orifice flow standard. Here, we use collision universality to measure $\langle σ_\mathrm{tot} v \rangle = 6.44(11)(5) \times 10^{-15}~\rm{m^3/s}$ for Rb-Rb collisions and deduce the corresponding $C_6 = 4688(198)(95)~E_ha_0^6$, in excellent agreement with predictions based upon $\textit{ab initio}$ calculated and previously measured $C_6$ values.
