Quantum-critical superconductivity in underdoped cuprates
Department of Physics, University of Wisconsin -
Madison, WI 53706, USA
2 Department of Physics and Ames Laboratory, Iowa State University Ames, IA 50011, USA
Accepted: 4 May 2001
We argue that the pseudogap phase may be an attribute of the non-BCS pairing of quantum-critical, diffusive fermions near the antiferromagnetic quantum critical point. We derive and solve a set of three coupled Eliashberg-type equations for spin-mediated pairing and show that in some T range below the pairing instability, there is no feedback from superconductivity on fermionic excitations, and fermions remain diffusive despite of the pairing. We conject that in this regime, fluctuations of the pairing gap destroy the superconducting condensate but preserve the leading edge gap in the fermionic spectral function.
PACS: 71.10.Ca – Electron gas, Fermi gas / 74.20.Fg – BCS theory and its development / 74.25.-q – Superconductivity: General properties; correlations between physical properties in normal and superconducting states
© EDP Sciences, 2001