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Prof. Ku Wei
Condensed Matter Theory Group
Brookhaven National Laboratory, USA |
Abstract: A generic theory of the quasiparticle superconducting gap in underdoped cuprates is derived in the strong-coupling limit, and found to describe the experimental “second gap” in absolute scale. In drastic contrast to the standard pairing gap associated with Bogoliubov quasiparticle excitations, the quasiparticle gap is shown to originate from anomalous kinetic (scattering) processes, with a size unrelated to the pairing strength. Consequently, the k dependence of the gap deviates significantly from the pure dx2y2 wave of the order parameter. Our study reveals a new paradigm for the nature of the superconducting gap, and is expected to reconcile numerous apparent contradictions among existing experiments and point toward a more coherent understanding of high-temperature superconductivity.
About the Speaker: Dr. Ku Wei is a physicist with the condensed matter theory group (condensed matter physics and materials science department) in Brookhaven National Laboratory. His current research interest includes study of electronic, optical, and magnetic properties of strongly correlated systems (including correlated nano-materials), and using state-of-the-art computational approaches. In addition, he is also developing novel theoretical/numerical methods to investigate systems with strong many-body interactions.
Date&Time: November 26, 2012 (Monday), 16:00–17:00
Location: 606 Conference Room