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100th QST-JAEA-UH Joint Condensed Matter Colloquium
24rd Open Seminar of Resear Center for New Functional Materials

“๚Žž: •ฝฌ29”N5ŒŽ16“๚(‰ฮ) 14:30`15:30
Date and time: 16th May (Tue.) 14:30-15:30
๊Š: SPring-8, –GŒ๕Šู
Place: SPring-8, "HOUKOUKAN" seminar room
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Title: Quantum criticality of semimetal-superconductor phase transition in Dirac fermions
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Speaker: Dr. Yuichi Otsuka (K-Computer Center)
Abstract:

We investigate a semimetal-superconductor phase transition of Dirac fermions by means of large-scale QMC simulations for the attractive Hubbard model on the triangular lattice, in which alternating magnetic π-flux is introduced to construct the linear dispersion of the Dirac fermions. This phase transition is expected to correspond to the chiral-XY class in the framework of the Gross-Neveu model, where an order parameter breaking the U(1) symmetry brings about the chiral-symmetry breaking and hence a mass gap. We calculate the order parameter of the s-wave superconductivity on large clusters with more than 1,600 lattice sites and obtain the critical exponents of the transition.


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“›ˆไŒ’“๑i—สŒคSPring-8j
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Organizers: Toru Sakai(University of Hyogo, QST SPring-8)
Kenji Tsutsui(QST Pring-8)
Hiroki Nakano(University of Hyogo)