Figure 1

Phase transition to BEC during the evaporative cooling. (a) Absorption images at different evaporation stages are shown with the TOF of 14 ms. Each image is 290 $\mu$m per side. (b) Corresponding integrated column densities along the horizontal direction are shown with laser powers of the horizontal FORT beam. The BEC transition is observed as an appearance of a bimodal distribution (middle). At the end of the evaporation, a almost pure condensate of $1.0\times 10$${}^4$ is produced (top). The absorption images are taken from an angle of 45${}^{\circ }$ against the horizontal FORT axis in the horizontal plane.Reuse & Permissions

Figure 2

Expansion of condensate after release from the trap. The radii of the condensate show asymmetry between the horizontal (circle) and vertical (square) direction. The solid lines are the fits using Castin-Dum model. The error bars are standard error.Reuse & Permissions

Figure 3

Stable Bose-Bose mixture of ${}^{168}$Yb-${}^{174}$Yb. Absorption images of (a) almost pure ${}^{168}$Yb BEC of $9\times 10$${}^3$ and (b) almost pure ${}^{174}$Yb BEC of $9\times 10$${}^3$. Both images are taken after the TOF time of 18 ms in a separate experimental run. The larger cloud size of ${}^{168}$Yb compared with ${}^{174}$Yb manifests the larger mean-field energy of the condensate of ${}^{168}$Yb compared with ${}^{174}$Yb.Reuse & Permissions