Electron Hole Ordering in La2CuO4+δ

Mehring, M.; Gergen, P.; Kessler, C.; Krämer, Steffen

doi:10.1007/978-3-642-78805-5_13

Cited by 2 publications

(4 citation statements)

References 19 publications

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“…In the absence of disorder, they will tend to form a devil's staircase [637,641]. Since each CDW is composed of alternating layers of a VHS phase and either a magnetic or metallic phase, a range of T c values will arise due to proximity effects between the two domain types [793].…”

Section: Superconductivitymentioning

confidence: 99%

“…Chayes, et al [640] have recently explored the competition between CDW order and superconductivity in such a model. Mehring and coworkers [641] have also applied Ising, as well as Ginsburg-Landau models to study the phase separation. The effect of Coulomb repulsion in arresting a phase separation at nanoscopic scales arises in many situations that have little to do with superconductivity.…”

Section: Calculations Of Nanoscale Phase Separationmentioning

confidence: 99%

“…In studying these phase separations, it will be important to develop new probes which are sensitive to the fine spatial scales and slow fluctuations. Thus, Mehring, et al [641] studied the La nuclear spin-lattice relaxation rate in La 2 CuO 4+δ ; they found that the ordinary longitudinal (T −1 1 ) and transverse (T −1 2 ) relaxation rates were insensitive to the phase separation onset, whereas a stimulated echo relaxation rate (T * −1 1 ), specially chosen for sensitivity to slow fluctuations, had a strong peak at 230K, the onset of phase separation. (On the other hand, Hammel, et al [696] found a large peak in ((T 1 T ) −1 ).…”

Section: O-doping Of La2cuo 4+δmentioning

confidence: 99%

“…Alternatively, a similar effect could arise from commensurability effects in a CDW phase: as the doping is varied, the CDW periodicity changes, and certain periodicities will lock in to the underlying crystal lattice periodicity. In the absence of disorder, they will tend to form a devil's staircase [637,641]. Since each CDW is composed of alternating layers of a VHS phase and either a magnetic or metallic phase, a range of T c values will arise due to proximity effects between the two domain types [793].…”

Section: Superconductivitymentioning

confidence: 99%

See 3 more Smart Citations

A survey of the Van Hove scenario for high-tc superconductivity with special emphasis on pseudogaps and striped phases

Markiewicz

1997

Journal of Physics and Chemistry of Solids

371

280

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The Van Hove singularity (VHS) provides a paradigm for the study of the role of peaks in the density of states (dos) on electronic properties. More importantly, it appears to play a major role in the physics of the high-Tc superconductors, particularly since recent photoemission studies have found that the VHS is close to the Fermi level in most of the high-Tc cuprates near the composition of optimum Tc. This paper offers a comprehensive survey of the VHS model, describing both theoretical properties and experimental evidence for the picture. Special topics discussed include a survey of the Fermi surfaces of the cuprates and related compounds, and an analysis of the reliability of the slave boson approach to correlation effects. While many properties of the cuprates can be qualitatively understood by a simple rigid-band-filling model, this is inadequate for more quantitative results, since correlation effects tend to pin the Fermi level near the VHS over an extended doping range, and can lead to a nanoscale phase separation. Furthermore, the peaks in the dos lead to competition from other instabilities, both magnetic and structural (related to charge density waves). A novel form of dynamic structural instability, involving dynamic VHS-Jahn-Teller effects has been predicted. Scattered through the literature, there is considerable experimental evidence for both nanoscale phase separation of holes, and for local, possibly dynamic, structural disorder. This review attempts to gather these results into a comprehensive database, to sort the results, and to see how they fit into the Van Hove scenario. Recent experiments on underdoped cuprates are found to provide a strong confirmation that the pseudogap is driven by a splitting of the VHS degeneracy.

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Section: Superconductivitymentioning

confidence: 99%

Section: Calculations Of Nanoscale Phase Separationmentioning

confidence: 99%