Coincidence between energy gaps and Kohn anomalies in conventional superconductors
نویسندگان
چکیده
منابع مشابه
Energy gaps and Kohn anomalies in elemental superconductors.
The momentum and temperature dependence of the lifetimes of acoustic phonons in the elemental superconductors lead and niobium were determined by resonant spin-echo spectroscopy with neutrons. In both elements, the superconducting energy gap extracted from these measurements was found to converge with sharp anomalies originating from Fermi-surface nesting (Kohn anomalies) at low temperatures. T...
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I present the detailed behavior of phonon dispersion curves near momenta which span the electronic Fermi sea in a superconductor. I demonstrate that an anomaly, similar to the metallic Kohn anomaly, exists in a superconductor’s dispersion curves when the frequency of the phonon spanning the Fermi sea exceeds twice the superconducting energy gap. This anomaly occurs at approximately the same mom...
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The relationship between the cuprate pseudogap (Δ(p)) and superconducting gap (Δ(s)) remains an unsolved mystery. Here, we present a temperature- and doping-dependent tunneling study of submicron Bi(2)Sr(2)CaCu(2)O(8+δ) intrinsic Josephson junctions, which provides a clear evidence that Δ(s) closes at a temperature T(c) (0) well above the superconducting transition temperature T(c) but far belo...
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The quantum corrections to the energies of the point optical phonon modes Kohn anomalies in graphene nanoribbons NRs are investigated. We show theoretically that the longitudinal optical LO modes undergo a Kohn anomaly effect, while the transverse optical TO modes do not. In relation to Raman spectroscopy, we show that the longitudinal optical modes are not Raman active near the zigzag edge, wh...
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ژورنال
عنوان ژورنال: Physical Review B
سال: 2011
ISSN: 1098-0121,1550-235X
DOI: 10.1103/physrevb.84.174523