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Three years after the discovery of superfluid He-3 was discovered,
Physicists first observed heavy fermion superconductivity, yet the
open mind-set required to embrace these results as a discovery, rather
than a materials artifact was lacking. It took the efforts of a brave
and determined set of heavy electron pioneers, to overcome this
resistance and change the mind-set. It is fasincating to imagine how
our field might have changed if our community could have been wildly
more adventurous. Moreover, it poses the interesting question - how
can we avoid the conservative errors of the past to embracing todays
new challenges posed by strongly correlated electron materials?
Today, we are increasingly concious of the convergence of magnetism and superconductivity in condensed matter physics, of the central role of spin as a driver for heavy electron metals and superconductors - not just as the glue of pairing - but as the basic fabric of these materials. Many of us suspect that the nexus of these phenomena lies at the quantum critical point that appears to present in heavy electron, cuprate and iron-based superconductors. I'll talk about how our ideas about spins and their role in correlated electron physics are changing. I want to talk about the severe challenges the physicists face in trying to describe the incompressible spin component of these materials. I'll discuss the all-important links between f- and d-electron materials and some of the new kinds of order we are encountering, including a hidden and topological order. |
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