Approaches to BEC in a two species magnetic trap

M. Siercke, Chris W. Ellenor, Fan Wang +3 more

Cheng-Dong Mi, Khan Sadiq Nawaz, Peng-Jun Wang +4 more

We report the production of 39K and 87Rb Bose–Einstein condensates (BECs) in the lowest hyperfine states | F = 1,mF = 1 〉 simultaneously. We collect atoms in bright/dark magneto-optical traps (MOTs) of 39K/87Rb to overcome the light-assisted losses of 39K atoms. Gray molasses cooling on the D1 line of the 39K is used to effectively increase the phase density, which improves the loading efficiency of 39K into the quadrupole magnetic trap. Simultaneously, the normal molasses is employed for 87Rb. After the microwave evaporation cooling on 87Rb in the optically plugged magnetic trap, the atoms mixture is transferred to a crossed optical dipole trap, where the collisional properties of the two species in different combinations of the hyperfine states are studied. The dual species BECs of 39K and 87Rb are obtained by further evaporative cooling in an optical dipole trap at a magnetic field of 372.6 G with the background repulsive interspecies scattering length a KRb = 34 a 0 (a 0 is the Bohr radius) and the intraspecies scattering length a K = 20.05a 0.

Konstantin E. Dorfman, Vitaly V. Kocharovsky

Jianjun Hu, Yin Jian-Ping

We propose a novel magnetic surface microtrap (i.e. a double Z-wire trap) for the study of two-species Bose-Einstein condensations. The spatial distributions of the magnetic fields from the double Z-wire configurations and their gradients and curvatures are calculated and analysed. The result shows that the proposed surface trap has double magnetic wells and can be continuously changed into a single-well trap by reducing the current in a straight wire, and the maximum field gradient greater than 5 × 10 4 G/cm and the maximum field curvature (at each trap centre) greater than 2.5 × 10 7 G/cm 2 can be generated in our double-well traps, which can be used to realize two-species Bose-Einstein condensations and to study the properties of double-well Bose-Einstein condensations and so on.

Zalihe Ozcakmakli, C. Yüce

胡建军, 印建平

We propose a novel magnetic surface microtrap(i.e. a double Z-wire trap) for the study of two-species Bose-Einstein condensations.The spatial distributions of the magnetic fields from the double Z-wire configurations and their gradients and curvatures are calculated and analysed.The result shows that the proposed surface trap has double magnetic wells and can be continuously changed into a single-well trap be reducing the current in a straight wire,and the maximum field gradient greater than 5×10^4G/cm and the maximum field curvature (at each trap centre) greater than 2.5×10^7G/cm^2 can be generated in our double-well traps,which can be used to realize two-species Bose-Einstein condensations and to study the properties of double-well Bose-Einstein condensations and so on