Eur. Phys. J. B 46, 187-191 (2005)
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

Abstract

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.