Pairing Interaction in the two-dimensional Hubbard model studied with a dynamic cluster quantum Monte Carlo approximation
- ORNL
- University of Cincinnati
- University of California, Santa Barbara
A dynamic cluster quantum Monte Carlo approximation is used to study the effective pairing interaction of a 2D Hubbard model with a near neighbor hopping $$t$$ and an on-site Coulomb interaction $$U$$ . The effective pairing interaction is characterized in terms of the momentum and frequency dependence of the eigenfunction of the leading eigenvalue of the irreducible particle-particle vertex. The momentum dependence of this eigenfunction is found to vary as $$(\cos k_x-\cos k_y)$$ over most of the Brillouin zone and its frequency dependence is determined by the $S=1$ particle-hole continuum which for large $$U$$ varies as several times $$J$$. This implies that the effective pairing interaction is attractive for singlets formed between near-neighbor sites and retarded on a time scale set by $$(2J)^{-1}$$. The strength of the pairing interaction measured by the size of the d-wave eigenvalue peaks for $$U$$ of order the bandwidth $8t$. It is found to increase as the system is underdoped.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). National Center for Computational Sciences (NCCS)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1003569
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 74, Issue 9; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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