Since the first Bose-Einstein condensation (BEC) was produced in 1995, scientists have cooled and trapped atoms in BECs to investigate various topics in quantum many-body systems. The confinement of the atom determines the apparent properties of a BEC. Therefore, scientists are interested in producing condensation from as many atomic species as possible. A BEC consisting of europium atoms was created for this purpose by Yuki Miyazawa of the Tokyo Institute of Technology and colleagues.
Strong, magnetic dipole-dipole interactions are used by europium atoms to communicate with each other because of their unusually symmetrical electronic structure. A BEC in which the spin-dependent interactions of atoms are lower than the dipole interactions - a hitherto unknown regime - must result from a combination of these properties.
As a result, this discovery opens the door to the discovery of new facts about spin.
To produce a BEC from europium, Miyazawa and colleagues constrained europium atoms in an optical trap consisting of two crossed lasers. The scientists used evaporative cooling to keep atoms concentrated where the lasers intersect while lowering the intensity of one of the lasers.
Group 5×104 formed a BEC with atoms. Miyazawa and his colleagues discovered that they could control the strength of these connections by adding a very low magnetic field to the BEC, using techniques to monitor short-range interactions between atoms. According to experts, the adoption of this control will enable scientists to develop brand new BEC quantum phases.
The scientists also discovered evidence that BEC collapse and the structure development within it are both caused by intense dipolar interactions of atoms in images of the spatial distributions of atoms. This observation indicates that the spin-dependent interactions are in competition with these dipolar actions within the BEC.