Speaker: Mariusz Gajda, Institute of Physics Polish Academy of Sciences

When: Thu, Feb 21, 4pm – 6pm

Where: CQT Seminar Room S15, Level 3

Talk on: Resonant Einstein-de Haas effect in a rubidium condensate.

Abstract: My talk will be devoted to dipolar interactions in atomic Bose-Einstein condensates of rubidium atoms. Magnetic dipole-dipole interaction between rubidium atoms in their ground state are very small but under some conditions they may lead to observable effects. Assuming the magnetic moments of all atoms are initially aligned along the magnetic field, numerical calculations show that after the field's direction is reversed atoms are transferred to other Zeeman states. Such transfer is allowed by the dipolar interaction which couples the spin and the orbital degrees of freedom. Therefore, the transferred atoms acquire an orbital angular momentum and start to circulate around the center of the trap. This is a realization of the Einstein-de Haas effect in systems of cold gases. I will show existence of resonances which amplify this phenomenon making it observable even in very weak dipolar systems.