Quasiparticle spectrum of the cuprate Bi2Sr2CaCu2O8+delta: Possible connection to the phase diagram

W. Sacks (1) , Tristan Cren (1) , Dimitri Roditchev (1) , Benoît Douçot (2)

1 INSP - Institut des Nanosciences de Paris
2 LPTHE - Laboratoire de Physique Théorique et Hautes Energies

We previously introduced [T. Cren , Europhys. Lett. 52, 203 (2000)] an energy-dependant gap function, Delta(E), that fits the unusual shape of the quasiparticle (QP) spectrum for both BiSrCaCuO and YBaCuO. A simple anti-resonance in Delta(E) accounts for the pronounced QP peaks in the density of states, at an energy Delta(p), and the dip feature at a higher energy, E-dip. Here we go a step further, our gap function is consistent with the (T,p) phase diagram, where p is the carrier density. For large QP energies (E >Delta(p)), the total spectral gap is Delta(E)similar or equal to Delta(p)+Delta(phi), where Delta(phi) is tied to the condensation energy. From the available data, a simple p dependance of Delta(p) and Delta(phi) is found, in particular, Delta(phi)(p)similar or equal to 2.3k(B)T(c)(p). These two distinct energy scales of the superconducting state are interpreted by comparing to the normal and pseudogap states. The various forms of the QP density of states, as well as the spectral function A(k,E), are discussed.

Mots clés: T-C SUPERCONDUCTORS; HIGH-TEMPERATURE SUPERCONDUCTORS; DENSITY-OF-STATES; VACUUM TUNNELING SPECTROSCOPY; D-WAVE SUPERCONDUCTORS; UNDERDOPED BI2SR2CACU2O8+DELTA; PRECURSOR SUPERCONDUCTIVITY; ELECTRONIC-SPECTRA; VORTEX CORES; ENERGY-GAP

Domaines: Supraconductivité [cond-mat.supr-con]

W. Sacks, Tristan Cren, Dimitri Roditchev, Benoît Douçot. Quasiparticle spectrum of the cuprate Bi2Sr2CaCu2O8+delta: Possible connection to the phase diagram. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2006, 74, pp.174517. ⟨10.1103/PhysRevB.74.174517⟩. ⟨hal-00449821⟩