Eur. Phys. J. B (2016) 89: 183
https://doi.org/10.1140/epjb/e2016-70268-2

Regular Article

Unconventional temperature dependence of the cuprate excitation spectrum

¹ Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), UMR 7590, Sorbonne Universités, UPMC Paris 6, 4 place Jussieu, 75252 Paris Cedex 05, France
² Institut des Nanosciences de Paris (INSP), UMR 7588, Sorbonne Universités, UPMC Paris 6, 4 place Jussieu, 75252 Paris Cedex 05, France

^a e-mail: Yves.Noat@insp.jussieu.fr

Received: 14 March 2016
Received in final form: 3 May 2016
Published online: 29 August 2016

Abstract

Key properties of the cuprates, such as the pseudogap observed above the critical temperature T_c, remain highly debated. Given their importance, we recently proposed a novel mechanism based on the Bose-like condensation of mutually interacting Cooper pairs [W. Sacks, A. Mauger, Y. Noat, Supercond. Sci. Technol. 28, 105014 (2015)]. In this work, we calculate the temperature dependent DOS using this model for different doping levels from underdoped to overdoped. In all situations, due to the presence of excited pairs, a pseudogap is found above T_c while the normal DOS is recovered at T^∗, the pair formation temperature. A similar behavior is found as a function of magnetic field, crossing a vortex, where a pseudogap exists in the vortex core. We show that the precise DOS shape depends on combined pair (boson) and quasiparticle (fermion) excitations, allowing for a deeper understanding of the SC to the PG transition.