论文标题
在狭窄的S波feshbach共振附近进行三体碰撞的缩放定律
Scaling law for three-body collisions near a narrow s-wave Feshbach resonance
论文作者
论文摘要
超电原子气体提供了一个可控制的系统，可以研究三体系统的非弹性过程，其中三体重组速率取决于散射长度的缩放。在具有各种相互作用强度的骨气系统中已经确认了这种量表，但是它们与费米原子的存在仍然难以捉摸。在这项工作中，我们报告了针对三体原子损失率的缩放定律的实验调查，其中两个组成部分$^6 $ li fermi气体，带有散射长度$ a <0 $。缩放定律在$ a $的一定范围内得到验证，附近狭窄的$ s $ wave feshbach共振，其中$ l_3 \ propto t | a | a |^{2.60（5）} $，$ t $是气体温度。观察到缩放定律在散射长度方面具有上限和下限。对于上限，当$ a \ rightarrow \ infty $时，由强烈的三体碰撞引起的共鸣的统一行为抑制了幂律缩放。对于下边界，$ a \ rightarrow 0 $，有限范围效应通过有效散射长度$ l_e $修改了缩放定律。这些结果表明，费米子系统中的三体重组率可以以与广义Efimov物理学相关的缩放定律为特征。
Ultracold atomic gases provide a controllable system to study the inelastic processes for three-body systems, where the three-body recombination rate depends on the scattering length scaling. Such scalings have been confirmed in bosonic systems with various interaction strengths, but their existence with fermionic atoms remains elusive. In this work, we report on an experimental investigation of the scaling law for the three-body atomic loss rate $L_3$ in a two-component $^6$Li Fermi gas with the scattering length $a<0$. The scaling law is validated within a certain range of $a$ near the narrow $s$-wave Feshbach resonance, where $L_3\propto T|a|^{2.60(5)}$, and $T$ is the gas temperature. The scaling law is observed to have an upper and a lower bound in terms of the scattering length. For the upper bound, when $a\rightarrow \infty$, the power-law scaling is suppressed by the unitary behavior of the resonance caused by the strong three-body collisions. For the lower bound, $a\rightarrow 0$, the finite range effect modifies the scaling law by the effective scattering length $L_e$. These results indicate that the three-body recombination rate in a fermionic system could be characterized by the scaling law associated with the generalized Efimov physics.
