Figure 1

Simultaneous optical trapping of ${}^6\mathrm{Li}$ and ${}^{174}\mathrm{Yb}$. (a) shows the typical experimental sequence where the laser cooling and ODT loading are performed sequentially for the two species. In addition to the standard procedures for single-species operation, the magnetic field gradients and the initial optical trap depths are adjusted for each species to optimize number and temperature. After both species are in the ODT, either (i) the power is held constant to study interspecies thermalization, or (ii) the power is ramped down to perform forced evaporative cooling. Finally, the optical trap is switched off and the remaining atoms detected with resonant absorption imaging. As displayed in (b), varying the Li MOT loading time ${\tau }_{\mathrm{Li}}$ allows us to control the initial ratio of the two species in the optical trap. The peak atom numbers correspond to $N_{\mathrm{Yb}(\mathrm{Li})}=11(4)\times {10}^5$, for trap depth $U_{\mathrm{Yb}(\mathrm{Li})}=0.5(1.1)\mathrm{mK}$. The dashed lines are exponential fits. The Yb decay time is substantially shorter than the background lifetime because of a partial overlap with the ${}^6\mathrm{Li}$ MOT during ${\tau }_{\mathrm{Li}}$. (c) Optical trapping potentials for Li and Yb for a given ODT power. The shading depicts the distributions at the same temperature.Reuse & Permissions

Figure 2

Sympathetic cooling of ${}^6\mathrm{Li}$ (red solid circles) by thermalization with a cold ${}^{174}\mathrm{Yb}$ bath (blue open squares). The temperatures equilibrate with an exponential time constant of $(1.7\pm 0.2)\mathrm{s}$ (black dashed line). The red solid line is the result of a numerical model (see text). The inset shows the numbers of the two species which are almost an order of magnitude apart.Reuse & Permissions

Figure 3

Sympathetic cooling of lithium by forced evaporative cooling of ytterbium. (a) Number and (b) temperature evolution for ${}^6\mathrm{Li}$ (solid circles) and ${}^{174}\mathrm{Yb}$ (open squares) as the power in the crossed optical dipole trap is reduced by a factor of 28 over 12 s, corresponding to an approximately exponential ramp with a time constant of 2.9 s.Reuse & Permissions