Monday, August 27, 2012

Finding order in the cuprate confusion

In Science last week there was a Perspective Cuprates Get Orders to Charge by John Tranquada about a paper that finds long-range charge order in YBCO in the same doping region at which quantum oscillations are observed. The Perspective is worth reading because it gives a nice overview of the issues.
On the other hand, I find it disappointing that Tranquada takes a view, similar  to other experimentalists, that little progress has been made in theory:
Although there are many theoretical proposals to describe this unusual “normal” state, no new simplifying paradigm has yet appeared.
I disagree. I think "plain vanilla" RVB theory does provide the simplifying paradigm. I acknowledge that not everyone agrees and there are still outstanding questions. But not all the theories out there are equal. There have varying amounts of supporting evidence and internal consistency.

My somewhat ill-informed and prejudicial view is that stripes, charge ordering, and quantum oscillations are a "red herring" which may only occur in some families of materials. The essential physics is in the RVB = Gutwiller projected BCS state and that these other phenomena are just perturbations on top of it.

I welcome other views.

1 comment:

  1. Thank you! As a layman (a biologist), I've long wondered about this. It's good to have an informed opinion so clearly stated.