Physics

16/09/2008

I want to take to the attention of the readers of the blog the new born online journal of American Physical Society simply called Physics. The idea is smart and consists in selecting certain papers published on APS journals, the well-known Physical Review series, and present them in a way to let the content usable by any physicist with the intent to cross-seminate ideas. The articles are written by experts of the field but aimed to a broad audience and so easy to be understood by whoever is doing active research in any area of physics. Papers are selected by editors of the Physical Review journals both by referees’ reports and internal discussions.

Personally I consider this a very successful idea. When I read journals like Nature, before entering into the reading of the article I am interested to, I read the corresponding “News and Views” article  written by some well-known expert of the field that makes clear to everybody its content. So, I think that this journal by APS was long overdue.


A significant progress in large molecule interferometry

16/09/2008

We have written several posts in this blog about the question of decoherence and thermodynamic limit. One of the crucial experiments to understand if a body made by a large number of molecules can become classical is through this ingenious way to do interferometry with large molecules. This idea has been realized by Anton Zeilinger and his group at University of Vienna using initially molecules of fullerene. The results were striking as they were able to prove the wave nature of these large molecules. The next step is to try to use more heavy bodies to do such an experiment. With their device, a Talbot-Lau interferometer, they were able to see wave behavior for fluorofullerene but in this case they obtained a visibility lower than expected (see here and here). They were unable to claim if this was a genuine new effect or rather a limitation of the experimental apparatus. Further analyses were needed but, mostly, the apparatus needed significant improvement to manage heavier molecules and to be sure in this way that any observed effect is a genuine one and not an artifact of the used device. Anyhow, I show here this picture that is really striking.

From this figure is blatantly evident that the expected curve is not in perfect agreement with measured points for fluorofullerene. But, as already said, the experimenters were not able to do any claim about this as these differences could be due to the interferometer.

Since then, all these activities have gone in the hands of Markus Arndt that worked with Zeilinger to these experiments. Arndt is full professor at University of Vienna and has taken in charge the not that easy activity to improve the apparatus to perform experiments with larger molecules. Recently Arndt and his group published a paper on Nature ( see here) where they showed a really significat improvement in the apparatus that should grant analysis of interferometry of very large molecules. We note in this way the complexity of this enterprise that required several years for the achievement. So, now the expectations are high to see interferometry with some unexpected kind of molecules and the possibility that Arndt and his group will do some breakthrough is surely high.


Follow

Get every new post delivered to your Inbox.

Join 66 other followers

%d bloggers like this: