High-resolution photoemission is used to study the electronic structure of the cuprate superconductor, Bi(2)Sr(2)CaCu(2)O(8+delta), as a function of hole doping and temperature. A kink observed in the band dispersion in the nodal line in the superconducting state is associated with coupling to a resonant mode observed in neutron scattering. From the measured real part of the self-energy it is possible to extract a coupling constant which is largest in the underdoped regime, then decreasing continuously into the overdoped regime.
We present results from the study of a highly overdoped (OD) Bi2Sr2CaCu2O 8+δ with a Tc = 51K using high resolution angle-resolved photoemission spectroscopy. The temperature dependent spectra near the (π, 0) point show the presence of the sharp peak well above Tc. From the nodal direction, we make comparison of the self-energy with the optimally doped and underdoped cuprates, and the Mo(110) surface state. We show that this OD cuprate appears to have properties that approach that of the Mo. Further analysis shows that the OD has a more k-independent lineshape at the Fermi surface than the lower-doped cuprates. This allows for a realistic comparison of the nodal lifetime values to the experimental resistivity measurements via Boltzmann transport formulation. All these observations point to the validity of the quasiparticle picture for the OD even in the normal state within a certain energy and momentum range.PACS numbers: 71.25. Hc, 74.25.Jb, 74.72.Hs, 79.60.Bm The question of whether the Fermi Liquid (FL) [1] model is a valid description for the high-T c superconductors has been one of the central issues in condensed matter. For the optimally doped (OP), and certainly the underdoped (UD) cuprates, there are many results which indicate that the FL picture may not be valid [2,3] especially in the normal state. It is speculated that as doping increases beyond the optimal value, the cuprate may become a FL.[4] However, experimental evidence from the highly overdoped (OD) regime showing FL properties is scant. Moreover, the FL term has become imprecise in recent literature. In the strictest definition of a FL, transport properties and the self-energy, Σ, of the single-particle excitations or quasiparticles (QP) are proportional to the square of binding energy, ω, and temperature, T , reflecting the electron-electron interactions. For regular metals, this is not the case for most T and ω because the electron-phonon interaction dominates the scattering rate and the resistivity. At the other extreme, the term FL has been used to describe any material that has well defined single-particle excitation regardless of the nature of the QP scattering or transport. In this Letter, we describe in detail the nature of Σ of the highly OD cuprate Bi 2 Sr 2 CaCu 2 O 8+δ (Bi2212). We find a state where there are well-defined single-particle excitations but the details do not match either a strict definition of a FL nor does Σ appear to be dominated by the electron-phonon interaction as found in normal metals. We use the term "quasiparticle liquid" (QPL) as a way to describe such a system that has: (i) well-defined single-particle excitations around the Fermi surface, and (ii) excitations that govern the transport properties even if these properties do not have the classic ω 2 and T 2 behavior or electron-phonon-like behavior.Angle-resolved photoemission spectroscopy (ARPES) is, in principle, the best method to determine the nature of the QP in a 2D solid. The presence of a sharp peak in the spectra potentially indicates the prese...
Ion transport through nanopores is a process of fundamental significance in nature and in engineering practice. Over the past decade, it has been found that the ion conductivity in nanopores could be drastically enhanced and different mechanisms have been proposed to explain this observation. To date, most reported studies have been carried out with relatively dilute electrolytes while ion transport in nanopores under high electrolyte concentrations (>1 M) has been rarely explored. Through systematic experimental and atomistic simulation studies with NaCl solutions, here we show that at high electrolyte concentrations, ion mobility in small nanopores could be significantly reduced from the corresponding bulk value. Subsequent molecular dynamics studies indicate that in addition to the low mobility of surface-bound ions in the Stern layer, enhanced pairing and collisions between partially dehydrated ions of opposite charges also make important contributions to the reduced ion mobility. Furthermore, we show that the extent of mobility reduction depends on the association constant between cations and anions in different electrolytes with a more drastic reduction for a larger association constant.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.