# What is the largest number of bosons placed in a BEC?

What is the record for the largest number of bosons placed in a Bose-Einstein condensate?

What are the prospects for how high this might get in the future?

EDIT: These guys reported 20 million atoms in 2008. "Large atom number Bose-Einstein Condensate machines". http://www98.griffith.edu.au/dspace/bitstream/handle/10072/21541/33525_1.pdf

EDIT 2: van der Straten's group reported 100-200 million.

But these guys don't seem to claim the largest BEC, so I wonder if there's larger.

EDIT 3: ~ 1 billion hydrogen atoms back in 2000 by Greytak et al.

http://www.sciencedirect.com/science/article/pii/S0921452699014155

Of course, hydrogen has only 1 nucleon while sodium (used by van der Straten et al.) has 23, so these are quite comparable in terms of mass.

• Hmm, are BEC coherent states? Do they have definite particle number? Coherent states are eigenstates of creation operator, a linear combination of states with all numbers of excitations... – innisfree Nov 25 '14 at 17:13
• I am pretty sure they are in number eigenstates for massive bosons like atoms. That's not even super important though, as coherent States are strongly peaked around a certain number for large N. – Jess Riedel Nov 25 '14 at 17:26
• OK, yes, $\delta n / n \propto 1/\sqrt{n}$ for a coherent state. What $n$ has been achieved... – innisfree Nov 25 '14 at 17:34
• It should be the highest one for atomic BEC, but if you also count for other quasi-particle BEC, it should be even higher. – unsym Nov 25 '14 at 18:21
• Do you mean Streed et al. is likely to be the highest atomic BEC? How high do you expect for quasi-particles, and who should I look at? – Jess Riedel Nov 25 '14 at 18:25