Electron mechanism for the structural phase transitions in La2−xBaxCuO4

Barišić, S.; Zelenko, J.

doi:10.1016/0038-1098(90)90504-5

Cited by 88 publications

(51 citation statements)

References 16 publications

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“…A first hint came from the discovery of the LTT phase in La 2−x Ba x CuO 4 , which was found to strongly suppress T c [401], and the subsequent realization that this phase does split the VHS degeneracy [402][403][404]. Based on this idea, the model of a Van Hove -Jahn-Teller (JT) effect was introduced [405][406][407], and it was postulated that both the LTO and HTT phases could be dynamic JT phases, with important short-range order.…”

Section: Electron-phonon Interactionmentioning

confidence: 99%

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

368

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: Electron-phonon Interactionmentioning

confidence: 99%

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

368

280

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“…1(d)]; this phase is associated with the development of charge-stripe and spin-stripe order. 74 In the x = 0.095 crystal close to T co ≃ T so ≃ T c the LTO structure undergoes a weakening of the orthorhombic strain, leading to a "low-temperature less orthorhombic" (LTLO) P ccn phase at very low temperature. In the x = 0.145 material the LTO→LTT transition occurs at ≃ 62 K, but charge order does not develop until T co ≃ 35 K and the spin order is likely very weak and is not observed; at low temperature the structure is thought to be a mixture of LTT+LTLO.…”

Section: Methodsmentioning

confidence: 99%

Determination of the optical properties of La2−xBaxCuO4
Homes
¹
,
Hücker
²
,
Li
³

et al. 2012
Phys. Rev. B
48
8
50
0
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The optical properties of single crystals of the high-temperature superconductor La2−xBaxCuO4 have been measured over a wide frequency and temperature range for light polarized in the a-b planes and along the c axis. Three different Ba concentrations have been examined, x = 0.095 with a critical temperature Tc = 32 K, x = 0.125 where the superconductivity is dramatically weakened with Tc ≃ 2.4 K, and x = 0.145 with Tc ≃ 24 K. The in-plane behavior of the optical conductivity for these materials at high temperature is described by a Drude-like response with a scattering rate that decreases with temperature. Below Tc in the x = 0.095 and 0.145 materials there is a clear signature of the formation of a superconducting state in the optical properties allowing the superfluid density (ρs0) and the penetration depth to be determined. In the anomalous 1/8 phase, some spectral weight shifts from lower to higher frequency ( 300 cm −1 ) on cooling below the spin-ordering temperature Tso ≃ 42 K, associated with the onset of spin-stripe order; we discuss alternative interpretations in terms of a conventional density-wave gap versus the response to pairdensity-wave superconductivity. The two dopings for which a superconducting response is observed both fall on the universal scaling line ρs0/8 ≃ 4.4σ dc Tc, which is consistent with the observation of strong dissipation within the a-b planes. The optical properties for light polarized along the c axis reveal an insulating character dominated by lattice vibrations, superimposed on a weak electronic background. No Josephson plasma edge is observed in the low-frequency reflectance along the c axis for x = 1/8; however, sharp plasma edges are observed for x = 0.095 and 0.145 below Tc.

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“…As mentioned above, an essential role of certain CuO 6 octahedra tilts in such stabilization can be supposed from experimental results 12,13,14,15 on lanthanum cuprates. It is known 26,27 that such tilts are strongly coupled to the carriers. This interaction can be described using an effective electrostatic potential φ l which is connected with the charge fluctuations δn l arising in Cu-O planes as a consequence of the tilts.…”

mentioning

confidence: 99%

Fluctuating charge-density waves in the Hubbard model

Sherman

Schreiber

2008

Phys. Rev. B

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The charge susceptibility of the two-dimensional repulsive Hubbard model is investigated using the diagram technique developed for the case of strong correlations. In this technique, a power series in the hopping constant is used. It is shown that once the Fermi level crosses one of the Hubbard subbands a sharp peak appears in the momentum dependence of the static susceptibility. With further departure from half-filling the peak transforms to a ridge around the Γ point. In the considered range 0 ≤ |1 −n| < ∼ 0.2 of the electron fillingn the static susceptibility is finite which points to the absence of the long-range charge ordering. However, for |1 −n| ≈ 0.12 the susceptibility maxima are located halfway between the center and the boundaries of the Brillouin zone. In this case an interaction of carriers with tetragonal distortions can stabilize the charge density wave with the wavelength of four lattice spacings, as observed experimentally in the lowtemperature tetragonal phase of lanthanum cuprates. In the range of parameters inherent in cuprate perovskites the character of the susceptibility evolution withn depends only weakly on the ratio of the nearest-neighbor hopping constant to the Hubbard repulsion and on details of the initial band structure. The location of the susceptibility maxima in the Brillouin zone is mainly determined by the value ofn.

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Electron mechanism for the structural phase transitions in La2−xBaxCuO4

Cited by 88 publications

References 16 publications

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

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

Determination of the optical properties of La2−xBaxCuO4
Homes
¹
,
Hücker
²
,
Li
³

et al. 2012
Phys. Rev. B
48
8
50
0
View full text Add to dashboard Cite

Fluctuating charge-density waves in the Hubbard model

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Electron mechanism for the structural phase transitions in La2−xBaxCuO4

Cited by 88 publications

References 16 publications

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

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

Determination of the optical properties of La2−xBaxCuO4Homes1, Hücker2, Li3 et al. 2012Phys. Rev. B488500View full textAdd to dashboardCite

Fluctuating charge-density waves in the Hubbard model

Contact Info

Product

Resources

About

Determination of the optical properties of La2−xBaxCuO4
Homes
¹
,
Hücker
²
,
Li
³

et al. 2012
Phys. Rev. B
48
8
50
0
View full text Add to dashboard Cite