Geometric scaling of Efimov states in a $^{6}\textrm{Li}$-$^{133}\textrm{Cs}$ mixture

Understand

In few-body physics, Efimov states are an infinite series of three-body bound states that obey universal discrete scaling symmetry when pairwise interactions are resonantly enhanced.

• Despite abundant reports of Efimov states in recent cold atom experiments, direct observation of the discrete scaling symmetry remains an elusive goal.
• Here we report the observation of three consecutive Efimov resonances in a heteronuclear Li-Cs mixture near a broad interspecies Feshbach resonance.
• The positions of the resonances closely follow a geometric series $1$, $\lambda$, $\lambda^2$.