Direct measurement of the heat capacity of a Bose-Einstein condensate
S. K. Ruddell,∗ D. H. White, A. Ullah,† and M. D. Hoogerland Department of Physics, University of Auckland, Private Bag 92019, Auckland, New Zealand
We transfer a known quantity of energy to a harmonically trapped Bose-Einstein condensate in order to study the resulting thermodynamics. We consider two methods, the first using a free expansion under gravity and the second using an optical standing wave to diffract the atoms in the potential. We investigate the effect of interactions on the resulting thermodynamics and compare our results to theory, with no adjustable parameters, providing a quantitative analysis of the heat capacity of our system.
By adding an adjustable phase to the delta-kicked rotor experiment we were able to generate a “flying island” of stability in this classically chaotic system. The results were published here:
Our all-optical BEC has been back for a little while, no real problems. We had some standard issues of shutters not shutting at the appropriate time, and magnetic fields not being what they should be, but everything is up and running. Atom numbers are comparable to previously, and we’re working on improving this.
After a lot of mucking around with overhead tables, the new labs overheating and non-working water cooling, we finally have both magneto-optical traps working. The dipole trap is lined up and ready to go. So BEC soon we hope.
