Quasiparticle spectrum of the cuprate BiSrCaCuO: Possible connection to the phase diagram

Abstract

We previously introduced [T. Cren et al., 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 $\Delta (E)\simeq {\Delta }_p+{\Delta }_{\varphi }$, where ${\Delta }_{\varphi }$ is tied to the condensation energy. From the available data, a simple $p$-dependance of ${\Delta }_p$ and ${\Delta }_{\varphi }$ is found, in particular ${\Delta }_{\varphi }(p)\simeq 2.3k_B{T}_c(p)$. These two distinct energy scales of the superconducting state are interpreted by comparing with 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.

References in corpus (4)

• Inhomogeneity Induces Resonance Coherence Peaks in Superconducting BSCCO
• Scanning Tunneling Spectroscopy on the novel superconductor CaC6
• Enhancement of electronic inhomogeneities due to out-of-plane disorder in Bi_2Sr_2CuO_{6+delta} superconductors observed by scanning tunneling spectroscopy
• The resonant magnetic mode: a common feature of high-$T_C$ superconductors

Cited by in corpus (5)

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• Relation between the one-particle spectral function and dynamic spin susceptibility in superconducting Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8-\delta }$
• Unconventional temperature dependence of the cuprate excitation spectrum
• Nature of c-axis coupling in underdoped Bi2Sr2CaCu2O8 with varying degrees of disorder
• Condensation mechanism of high-$T_c$ cuprates: the key role of pairon excitations