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
Key properties of the cuprates, such as the pseudogap observed above the critical temperature Tc, 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 Tc 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.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2016