After the Black Forest meeting on Quantum Efficiency I flew straight to Sydney for another conference, without even returning home to Brisbane. I landed at 7am and walked in just as the conference welcome from the local Dean of Science was ending. I don't normally do crazy things like this. I am at University of NSW (where I worked from 1994-2000) for the Gordon Godfrey Workshop on Spins and Strong Correlations. Alex Hamilton and Oleg Sushkov are to be commended for the great list of overseas speakers they have attracted. Hopefully I will write something about some of the talks. I managed to stay awake (more or less) until afternoon tea but then had to leave...
Some of the questions I think we need to keep asking for the diverse array of solid materials under study include:
- What properties of a class of materials are universal?
- What are the broken symmetries (and order parameters) associated with the different ordered phases?
- What are the experimental signatures of strong electronic correlations? or, What properties cannot be explained even qualitatively by mean-field theory.
- Is the quality/purity of the samples high enough we can be confident that experimentalists are measuring what they claim on what they claim?
- What is the minimal quantum many-body Hamiltonian that can describe a class of materials? How many bands are necessary?
- Is there an variational wave function that captures the essential physics of the competition between the different ground states?
- Is the reliability of a theoretical approximation or numerical method high enough that we can be confident that theorists are calculating what they claim on the model they are studying?
- What are the outstanding unresolved questions?