New Theory: from Superfluids to Higgs mechanism

Naty1
Messages
5,605
Reaction score
40
Theorem unifies superfluids and other weird materials

http://newscenter.berkeley.edu/2012/06/08/theorem-unifies-superfluids-and-other-weird-materials/

Nambu Goldstone bosons...of the Higgs Mechanism!..and phonons...from Cosmology to materials design.

“Surprisingly, the implications of spontaneous symmetry breaking on the low energy spectrum had not been worked out, in general, until the paper by Watanabe and Murayama,”

Thoughts? Insights?? Sounds BIG to this observer.

I came across this while trying to learn more about the Higgs mechanism for 'creating' mass during the Big Bang. Very unexpected to find this!
 
Physics news on Phys.org
While this is interesting (I attended a seminar recently that covered the same type of topic), it is not surprising. Note that Anderson's work on broken symmetry greatly influenced the subsequent formulation of the Higgs mechanism, so that came directly out of condensed matter.

This is just one of the numerous examples where condensed matter formulations are being applied in areas that are considered to be "fundamental physics".

Zz.
 
Laughlin and Pines also ranted a bit on the same line, in their article "The theory of everything" (PNAS 97 28 (2000)):
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC26610/
For example, they also point the relationship between the Higgs mechanism and conventional superconductivity; and that ultimately such links exist because in general low-energy phenomena do not depend on the details of the microscopic systems and are universal in some sense. The theorem this press release applies to (http://prl.aps.org/abstract/PRL/v108/i25/e251602) does a contribution to shed some more light on the "in some sense" part. It is not a new theory, just a theorem in a context which is known to be relevant in many areas of physics. I cannot judge how important this particular insight is, but maybe some other person might.

At this moment this looks to me like a standard press release which... let's say... might transport a somewhat overoptimistic view of the impact of a particular publication of the same institution. I've seen the same kind of press release applied for other articles in my own field, to articles which really did nothing extraordinary. You need to be careful with such things. It's advertisement by a university for itself.
 
The article is available at arxiv:
http://arxiv.org/abs/1203.0609
It is about counting the number of Goldstone bosons in ron-relativistic systems. This is quite interesting as for example there are no Goldstone bosons for broken rotational symmetry.
An easy theory when we have to count with Goldstone bosons would be quite useful.
 
DrDu said:
The article is available at arxiv:
http://arxiv.org/abs/1203.0609
It is about counting the number of Goldstone bosons in ron-relativistic systems. This is quite interesting as for example there are no Goldstone bosons for broken rotational symmetry.
An easy theory when we have to count with Goldstone bosons would be quite useful.

Glancing briefly at the paper, it's not clear to me that their result is consistent with your statement.

For example, suppose rotational symmetry is broken e.g. down to rotations about the z-axis. Then we have two broken generators, Jx and Jy, but even if <Jz> is non-zero, there is no way 2 - 0 = (1/2)*rank since the rank is <= 3. Of course, their counting is consistent with the single gb in a ferromagnet.

What gives?
 
More generally, its not clear how general their result is. Does it work for spacetime symmetries (a classic question even in the relativistic context)? What if the system is on a lattice and doesn't have rotational invariance at all?

At the moment I can't tell if its more than just a formalization of the old fact that ferromagnets have one gb while antiferromagnets have two, but then i wonder if their formula is really so much better than just writing down the effective theory? Nevertheless, I don't want to downplay their formula too much as it is an interesting achievement.
 
Also, in my opinion you should ignore the hype about material design and so forth. It's a neat result in an old field (which makes it more impressive), but at the end of the day its still information contained in the low energy theory which we understand very well (for goldstone bosons).
 
"We assume spatial translational invariance
and rotational invariance at sufficiently long distances in
the continuum limit, while we can still discuss their SSB."
I am not quite sure what they mean here.
 
Back
Top