All-optical production of chromium Bose-Einstein condensates

Abstract

We report on the production of ${}^{52}\mathrm{Cr}$ Bose-Einstein condensates with an all-optical method. We first load $5\times {10}^6$ metastable chromium atoms in a one-dimensional (1D) far-off-resonance optical trap (FORT) from a magneto-optical trap, by combining the use of radio-frequency sweeps and depumping toward the ${}^{5}S_2$ state. The atoms are then pumped to the absolute ground state, and transferred into a crossed FORT in which they are evaporated. The fast loading of the 1D FORT ($35\mathrm{ms}$ $1∕e$ time) and the use of relatively fast evaporative ramps allow us to obtain in $20\mathrm{s}$ about $15000$ atoms in an almost pure condensate.