Doping Dependence of Two Energy Scales in the Tunneling Spectra of Superconducting La2-xSrxCuO4

Kato, Takuya; Maruyama, Toshiyuki; Okitsu, S.; Sakata, Hideaki

doi:10.1143/jpsj.77.054710

Cited by 29 publications

(70 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the photoemission lineshape broadens and the pseudogap increases when doping is reduced from the overdoped side of the phase diagram 47 . The same trend has been reported by STM studies of the density-of-states 63,64 . The exact experimental relation between scattering and pseudogap (normal state gap) has, however, not been discussed much 65 .…”

Section: B Spectral Gap and Scatteringsupporting

confidence: 87%

Electron scattering, charge order, and pseudogap physics inLa1.6−xNd0.4SrxCuO4: An angle-resolved photoemission spectroscopy s

Matt¹,

Fatuzzo²,

Sassa³

et al. 2015

Phys. Rev. B

View full text Add to dashboard Cite

We report an angle-resolved photoemission study of the charge stripe ordered La1.6−xNd0.4SrxCuO4 system.A comparative and quantitative line shape analysis is presented as the system evolves from the overdoped regime into the charge ordered phase. On the overdoped side (x = 0.20), a normal state anti-nodal spectral gap opens upon cooling below 80 K. In this process spectral weight is preserved but redistributed to larger energies. A correlation between this spectral gap and electron scattering is found. A different lineshape is observed in the antinodal region of charge ordered Nd-LSCO x = 1/8. Significant low-energy spectral weight appears to be lost. These observations are discussed in terms of spectral weight redistribution and gapping originating from charge stripe ordering.

show abstract

Section: B Spectral Gap and Scatteringsupporting

confidence: 87%

Electron scattering, charge order, and pseudogap physics inLa1.6−xNd0.4SrxCuO4: An angle-resolved photoemission spectroscopy s

Matt¹,

Fatuzzo²,

Sassa³

et al. 2015

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…Also, Andreev reflection experiments revealed a much smaller gap edge than the bias at the tunnelling conductance maxima in a few underdoped cuprates [11]. Another remarkable observation is the spatial nanoscale inhomogeneity of the pseudogap observed with STS [6,7,8] and presumably related to an unavoidable disorder in doped cuprates, Fig.1a. Essentially, the doping and magnetic field dependence of the superconducting gap compared with the pseudogap and their different real space profiles have prompted an opinion that the pseudogap is detrimental to superconductivity and connected to a quantum critical point rather than to preformed Cooper pairs [9].…”

mentioning

confidence: 93%

“…Present-day scanning tunnelling (STS) [6,7,8], intrinsic tunnelling [9] and angle-resolved photoemission (ARPES) [5] spectroscopies have offered a tremendous advance into the understanding of the pseudogap phenomenon in cuprates and some related compounds. Both extrinsic (see [6,8] and references therein) and intrinsic [9] tunnelling as well as high-resolution ARPES [5] have found another energy scale, reminiscent of a BCSlike "superconducting" gap that opens at T c accompanied by the appearance of Bogoliubov-like quasi-particles [5] around the node. Earlier experiments with a timeresolved pump-probe demonstrated two distinct gaps, one a temperature independent pseudogap and the other a BCS-like gap [10].…”

mentioning

confidence: 99%

Superconducting Gap, Normal State Pseudogap, and Tunneling Spectra of Bosonic and Cuprate Superconductors

Alexandrov

Beanland

2010

Phys. Rev. Lett.

View full text Add to dashboard Cite

We develop a theory of normal-metal -superconductor (NS) and superconductor -superconductor (SS) tunnelling in "bosonic" superconductors with strong attractive correlations taking into account coherence effects in single-particle excitation spectrum and disorder. The theory accounts for the existence of two energy scales, their temperature and doping dependencies, asymmetry and inhomogeneity of tunnelling spectra of underdoped cuprate superconductors.PACS numbers: 74.40.+k, 72.15.Jf, 74.25.Fy Soon after the discovery of high-T c superconductivity [1], a number of tunnelling, photoemission, optical, nuclear spin relaxation and electron-energy-loss spectroscopies discovered an anomalous large gap in cuprate superconductors existing well above the superconducting critical temperature, T c . The gap, now known as the pseudogap, was originally assigned [2] to the binding energy of real-space preformed hole pairs -small bipolarons -bound by a strong electron-phonon interaction (EPI). Present-day scanning tunnelling (STS) [6,7,8], intrinsic tunnelling [9] and angle-resolved photoemission (ARPES) [5] spectroscopies have offered a tremendous advance into the understanding of the pseudogap phenomenon in cuprates and some related compounds. Both extrinsic (see [6,8] and references therein) and intrinsic [9] tunnelling as well as high-resolution ARPES [5] have found another energy scale, reminiscent of a BCSlike "superconducting" gap that opens at T c accompanied by the appearance of Bogoliubov-like quasi-particles [5] around the node. Earlier experiments with a timeresolved pump-probe demonstrated two distinct gaps, one a temperature independent pseudogap and the other a BCS-like gap [10]. Also, Andreev reflection experiments revealed a much smaller gap edge than the bias at the tunnelling conductance maxima in a few underdoped cuprates [11]. Another remarkable observation is the spatial nanoscale inhomogeneity of the pseudogap observed with STS [6,7,8] and presumably related to an unavoidable disorder in doped cuprates, Fig.1a. Essentially, the doping and magnetic field dependence of the superconducting gap compared with the pseudogap and their different real space profiles have prompted an opinion that the pseudogap is detrimental to superconductivity and connected to a quantum critical point rather than to preformed Cooper pairs [9]. Nevertheless without a detailed microscopic theory that can describe highly unusual tunnelling and ARPES spectra, the relationship between the

show abstract

Section: Introductionmentioning

confidence: 99%

“…The normal phase properties differs completely from the BCS superconductors. It is a matter of intense debate whether this problem is connected with the charge inhomogeneities observed in many different experiments [3,4,5,6,7,8,9,10].In order to obtain a unified interpretation to all of these observations we studied an electronic phase separation (EPS) transition that generates regions of low and high densities. Such a transition may be driven by the lower free energy of undoped antiferromagnetic (AF) regions[11] (intrinsic) or by the out of plane dopants[12] (extrinsic origin).…”

mentioning

confidence: 99%

Competing orders in the phase diagram of cuprate superconductors

Magalhães

Mello

2012

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract.We perform self-consistent calculations in the framework of the Bogoliubov-deGennes theory with a model Hubbard Hamiltonian with strong local correlations. The calculations are performed in a charge density disordered system to study the competition of charge inhomogeneity, spin disorder and superconductivity These calculations are appropriate to describe the cuprate superconductors' phase diagram with the competition of different phases. We find that, in the presence of charge disorder the spin density wave (SDW) order occurs at higher temperatures above the opening of the superconducting gap. This is in opposition to the homogeneous systems where the SDW phase appears in the low doping compounds in the superconducting phase. These finding provides an explanation to the non-Fermi liquid behavior of the cuprates normal phase. IntroductionThe origin of the superconducting gap associated with the superconducting state and the relation to the pseudogap above the transition temperature (T c ) remains one of the central questions in high-T c research [1,2]. The normal phase properties differs completely from the BCS superconductors. It is a matter of intense debate whether this problem is connected with the charge inhomogeneities observed in many different experiments [3,4,5,6,7,8,9,10].In order to obtain a unified interpretation to all of these observations we studied an electronic phase separation (EPS) transition that generates regions of low and high densities. Such a transition may be driven by the lower free energy of undoped antiferromagnetic (AF) regions[11] (intrinsic) or by the out of plane dopants[12] (extrinsic origin).In this context we perform the study of the the superconducting (SC) and antiferromagnetic (AF) order in a model t-t'-U-V Hamiltonian commonly used to describe the cuprates [13,14] in an electronic disordered system. Chen and Ting [14] have studied this model for different doping and temperature and found that the AF is stronger at low doping and high temperatures. Self-consistent calculations in the Bogoliubov-deGennes (BdG) framework indicates that the AF order persists above the opening of the SC order parameter at very high temperatures. This is used to interpret the normal pseudogap phase, since this type of spin density wave will cause an additional scattering to the electrons and will change the Fermi liquid properties.

show abstract

Doping Dependence of Two Energy Scales in the Tunneling Spectra of Superconducting La_2-xSr_xCuO₄

Cited by 29 publications

References 33 publications

Electron scattering, charge order, and pseudogap physics inLa1.6−xNd0.4SrxCuO4: An angle-resolved photoemission spectroscopy s

Electron scattering, charge order, and pseudogap physics inLa1.6−xNd0.4SrxCuO4: An angle-resolved photoemission spectroscopy s

Superconducting Gap, Normal State Pseudogap, and Tunneling Spectra of Bosonic and Cuprate Superconductors

Competing orders in the phase diagram of cuprate superconductors

Contact Info

Product

Resources

About