Creation of ¹⁷⁴Yb Bose–Einstein Condensates in a Crossed FORT

Quantum degenerate gases of alkaline-earth-like atoms are unique systems used for quantum simulation, quantum computing and studies of quantum phase transitions. We report an all-optical formation of Bose–Einstein condensates of ytterbium atoms. About 10⁶ atoms of ¹⁷⁴Yb are transferred to a far-off-resonance optical trap (FORT) and then cooled by evaporative cooling. Phase transition occurs at the critical temperature of 520 nK. A pure condensate containing approximately 2×10⁴ atoms has been obtained in the crossed FORT, with an atomic peak density of ～8×10¹⁴ cm^?3. The condensate lifetime exceeds 1 s.