https://doi.org/10.1140/epjb/e2005-00252-x
Evidence for a metallic–like state in the T = 0 K phase diagram of a high temperature superconductor
1
Departamento de Matemática, CCNE, Universidade Federal de Santa Maria, 97105-900
Santa Maria, RS, Brazil
2
Departamento de Física–FACYT, Universidad de
Carabobo, Valencia 2001, Edo. Carabobo, Venezuela
3
Department of Physics and Astronomy, University of
Iowa, Iowa City, IA 52242, USA
and Department of Theoretical Physics, University of Cluj, Cluj 3400, Romania
Corresponding author: a ionel-tifrea@uiowa.edu
Received:
16
December
2004
Revised:
10
February
2005
Published online:
11
August
2005
We examine the effects of a phenomenological pseudogap on the T=0 K phase diagram of a high temperature superconductor within a self-consistent model which exhibits a d-wave pairing symmetry. At the mean-field level the presence of a pseudogap in the normal phase of the high temperature superconductor is proved to be essential for the existence of a metallic–like state in the density versus interaction phase diagram. In the small density limit, at high attractive interaction, bosonic–like degrees of freedom are likely to emerge. Our result should be relevant for underdoped high temperature superconductors, where there is a strong evidence for the presence of a pseudogap in the excitation spectrum of the normal state quasiparticles.
PACS: 74.20.Fg – BCS theory and its development / 74.20.-z – Theories and models of superconducting state / 74.60.-w – Type-II superconductivity / 74.72.-h – Cuprate superconductors (high-Tc and insulating parent compounds)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005