14 DAY TRIAL // In 2008, the US Defense Advanced Research Projects Agency (DARPA) has commissioned three multi-university scientific teams to investigate the possibility of developing a technology that would allow for trapping various types of atoms into micro-scale “light crystals,” also designated as optical lattices. Controlling atomic movement in this fashion would allow for the creation of new classes of materials that, at least in theory, have the potential to revolutionize the entire field of physics, super conductive material sciences, as well as construction sciences altogether.
The first phase of the DARPA project is coming to an end in June 2009, and the science team still have little to show after more than a year of constant research. Still, not all hope is lost. Tin-Lun Ho and doctoral student Qi Zhou, both physicists at the Ohio State University (OSU), have published in this week's online edition of the journal Proceedings of the National Academy of Sciences (PNAS) what can very well be considered a breakthrough in the research. The two experts believe they may have found a potential solution to the problems that have been halting their advance.
The main issue with constructing optical lattices is the fact that the atoms to be contained inside have to be completely cooled down, so as to make them as less agitated as possible. In order for this to happen, heat has to be artificially “squeezed out” of them. Ho and Zhou believe that, by compressing the target atoms into a small space, they could force the heat out. It would then be taken over by a pool of super-cool Bose-Einstein condensate (BEC), a special solution that can take all the heat and immediately dissipate it.
“It is absolutely essential to achieve very low temperatures for this program to succeed. All three teams have made much progress, but until now, temperature has been a bottleneck for the whole enterprise. Ours is the first proposal to show how the temperature can be lowered dramatically. In fact, we believe it can be made much lower that what is considered achievable today,” Ho, who is also an OSU Distinguished professor of mathematical and physical sciences, explains.
“Effectively, this is a two-part solution – divide and conquer. The 'divide' part is to push the entropy out of the interior of the system. The 'conquer' part is to get rid of the entropy by evaporating away the BEC. Next, we'd like to reduce it to a one-step process, and eliminate the need for the BEC entirely,” the expert concludes.