AlbaNova and Nordita Colloquium
Eunseong Kim (Department of Physics, KAIST, Republic of Korea)
FR4 Oskar Kleins Auditorium
Thursday 10 November
15:00 - 16:00
Below 2.176K, liquid 4He enters into a superfluid state and flows without any friction. The onset of superfluidity is associated with Bose-Einstein Condensation where 4He atoms, which are bosons, condense into a single momentum state and acquire quantum mechanical coherence over a macroscopic length scale. In 1972, superfluidity in liquid 3He through p-wave pairing was discovered below 2mK. Bose-Einstein condensation in alkali atoms in the vapor phase was achieved in 1995 and there is strong evidence for superfluidity in the system. Perhaps counter to intuition, superfluid-like behavior is thought possible even in solid 4He. First experimental confirmation of this supersolid state has not been achieved until the experiments of Kim and Chan.  Despite many efforts to uncover the mechanism of supersolidity since the first observation of non-classical rotational inertia in solid helium, the microscopic origin and physical interpretation of the observed phenomena is still a subject of considerable intrigue. In this talk, I will review and correlate recent experimental results to provide an up-to-date picture of what we do and still do not understand. I will also take the opportunity to highlight the recent progress in solid helium experiment under rotation.
1. E. Kim and M. H. W. Chan, Nature 427, 225 (2004)