Thursday, September 19, 2013

A political metaphor for the correlated electron community

It is the conservatives vs. the radicals, the right vs. the left.

A colleague recently suggested to me that this is a good metaphor or analogue for describing and understanding the divisions in the physics community working on the theory of correlated electron materials.

In the USA political divisions have led to a "gridlock" that is stopping the country moving forward. Both conservatives and liberals have a rigid ideology that prevents them from seeing the merits
of their opponents concerns and from being willing to compromise. Conservatives believe one should never raise taxes. Liberals believe one should never cut social welfare programs.
Both "cherry pick" economic data to support their point of view.

Historically, political radicals believe that capitalism is a flawed and unstable system that must be replaced by some new, but unknown, system.

The world is more complex than political ideology concedes.
Both radicals and conservatives have extreme beliefs that I sometimes find simplistic.
"The only way to reduce crime is to put more people in prison."
"Crime is just a result of social injustice."
"Poverty can only be solved by economic growth. That means less taxes on big business and the wealthy."
"The poor are helpless. Government welfare programs will solve their problems."

I really like the book Poor Economics because the authors [MIT economists Abhijit Banerjee and Esther Duflo] do not see the developing world through the extreme eyes of the left [represented by Jeffrey Sachs] or the right [represented by William Easterly].
Instead, the authors actually do randomised trial experiments to obtain empirical data to see what does and does not work in poverty alleviation. They find that sometimes the right is correct and sometimes the left is correct. Sometimes neither. The world is complex.

So what does this have to do with the theory of correlated electron materials?
On one side we have the conservatives who believe that the key ingredients are atomistic detail, good density functionals, perturbation theory, mean-field theory, and the random-phase approximation.
New concepts and methods are not really needed. They have a good system [just like capitalism].
In particular, we don't need a revolution, just bigger computers!
Perhaps they are represented by Igor Mazin, David Singh, Warren Pickett, Olle Andersen, ... The former three all have a career connection to Naval Research Laboratory.
Unlike the radicals below, it is not clear to me that the conservatives have a clear ideological or inspirational leader.

The radicals believe in universality. Atomistic detail is largely irrelevant. It is all about collective behaviour [not individuality].
Completely new conceptual structures and techniques are needed. We must go beyond Landau's mean-field theory and Fermi liquid theory: topological order, quasi-particles with fractional quantum numbers, AdS-CFT, quantum criticality, ...
To the barricades!
Phil Anderson is an enduring inspiration for the radicals just as Marx still is for political radicals.
Indeed many of the radicals [Wen, Patrick Lee, Viswanath, Haldane, ...] have some historical connection to Princeton or Anderson.
I think Anderson is like Marx in that he defines the problems, and asks the hard questions; but I am not sure the answers are right.
But for some, even Marx is not radical enough.
Perhaps, Subir Sachdev is like Lenin with his AdS/CFT comrades. Anderson accuses them of "quasi-journalism". Perhaps, just like Leninists they consider propaganda is also good for their cause.
Bob Laughlin is an aging dis-illusioned radical who has become dis-engaged from the political process. He was a Berkeley undergrad, after all!
Perhaps, Piers Coleman is like a European Social Democrat.

Each side is largely dis-engaged from the other and appears unwillingly to acknowledge the merits of their opponents point of view. This is bad for the field, just like uncompromising political divisions are bad for countries.

Gabi Kotliar has roots on the left, but is moving more towards the right as he grows older.  He and Andy Millis are probably a disappointment to both the left and the right, just like Obama!
I am also caught in the middle, with slightly more sympathy for the left than the right, just like in politics. As in politics, I am troubled at some of the extreme views I see on both the left and right. Inconvenient data is ignored.

Can the community move beyond ideology, see and respect others point of view, and work together?
It is interesting that topological insulators have actually led to some constructive dialogue and co-operation between left and right.

Aside: What about the theoretical chemistry community?
I feel it is dominated by the conservatives. Do they need some radicals to shake them up?

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  1. Interesting post.

    Although, it would be nice if you might clarify your point about new concepts and methods not being needed for the 'conservatives'; because new *computational* concepts and methods indeed need to be developed for the 'conservatives', which can be radical. I'm guessing you meant it, but I thought I'd mention it.

    In which regard, I quite like a quotation by Donald Knuth: "It is said that people understand something only when they can explain it to others; but it seems to me that people really understand something only when they can explain it to a computer."

    1. There are some political conservatives who don't think anything should change. There are also "radical" conservatives who also want to change things radically. e.g., abolish welfare, privatise everything, ...

      I think there are correlated electron conservatives who are only looking for incremental improvements in methods. There are some who are trying to develop completely new computational methods.

  2. I enjoyed this immensely, and I'm fighting the urge to add more names to your dictionary...

    One glitch in the analogy is that, while political radicals usually see their ideas as a means to achieve a better society, I don't think that the radical strand in condensed matter that you identify sincerely believe that their approach will give us a better understanding of the solid state. If real materials are too boring to go ahead and dress themselves in the wonderful vestments provided, well, more fool them (goes the attitude)!

    This comes back to the question I often ponder: do explanations of novel phenomena require novel concepts? We are certainly hooked on this idea in condensed matter. But isn't it conceivable that -- to take the obvious example -- High Tc could be understood by supplying a sufficiently accurate numerical technique to a sufficiently realistic model? One could imagine discovering that the ground state of such a system was superconducting, despite the proximity to the Mott state, while low lying excited states don't have a simple quasiparticle interpretation, and the system just behaves like a strongly interacting soup.

    If this happened (I'm finessing the issue of computational complexity here, which may be the crucial weakness of this argument), would we be able to say we understood High Tc? Do we have the right to expect something more?

  3. Thanks for the comment, Austen.

    All analogues and metaphors are imperfect. This one certainly is. However, I think your suggestion of where it breaks down, actually highlights the similarity to me. You question the sincerity of the correlated electron radicals. This also often happens in politics. People on both the right and the left question the sincerity of their opponents. Whereas, I think many on the extreme left and right do have the best interests of society at heart. Obviously, not all - some may be more concerned about their own best interest, both on the left and right.

  4. So when is the Soviet Union going to collapse. Who takes the role of Andropov, Tschernyenko and Gorbatchov ...

    1. One can equally well ask, "When will the Global Financial Crisis occur?". Although, some might say that happened in 1986 with the discovery of the cuprate superconductors?

  5. HILLARIOUS Ross!!! And totally true. You are right, DMFT people are like Mussolini, who represented a compromise between the Left and the Right, which were also grid-locked in the 1920s Italy. This is how Mussolini quickly came to power, and ruled with the iron fist for 20 years.

    However, he soon ended arrested and killed, then stripped naked and hung upside down by his legs from a tall tree. I hope the same will not be the fate of Gabi Kotliar and DMFT, which I cherish... :-)