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Center for Nonlinear Studies |
Prior to the advent of the Bardeen-Cooper-Schrieffer theory in 1957, superconductivity had been referred to as the shame of quantum mechanics. It took forty-six years after the first observation of this phenomenon to arrive at a coherent explanation. Over the past two decades (three according to some) we have seen a recurrence of this, when superconductivity was discovered in a number of materials in which there exist strong repulsive electron-electron interactions, and which therefore lie outside the scope of the BCS theory. One approach to this new class of materials has been to focus on their magnetic behavior. The concept of a quantum spin liquid (QSL) has acquired popularity, but not necessarily success. In this talk I will discuss the need to go beyond QSL theories, and develop the concept of a paired-electron crystal (PEC), which is a semiconductor with paired electrons. I will then posit that a superconductor is a paired-electron liquid, and present justifications based on experiments. The talk is directed towards nonexpert graduate students. Experts will find overlaps with the RVB theory, the bipolaron theory and stripe concepts.
Host: Bob Ecke, ecke@lanl.gov, 7-6733