Multiorbital charge-density wave excitations and concomitant phonon anomalies in Bi2Sr2LaCuO6+δ

Charge-density waves (CDWs) are ubiquitous in underdoped cuprate superconductors. As a modulation of the valence electron density, CDWs in hole-doped cuprates possess both Cu-3dand O-2porbital character owing to the strong hybridization of these orbitals near the Fermi level. Here, we investigate underdoped Bi2Sr1.4La0.6CuO6+δusing resonant inelastic X-ray scattering (RIXS) and find that a short-range CDW exists at both Cu and O sublattices in the copper-oxide (CuO2) planes with a comparable periodicity and correlation length. Furthermore, we uncover bond-stretching and bond-buckling phonon anomalies concomitant to the CDWs. Comparing to slightly overdoped Bi2Sr1.8La0.2CuO6+δ, where neither CDWs nor phonon anomalies appear, we highlight that a sharp intensity anomaly is induced in the proximity of the CDW wavevector (QCDW) for the bond-buckling phonon, in concert with the diffused intensity enhancement of the bond-stretching phonon at wavevectors much greater than QCDW. Our results provide a comprehensive picture of the quasistatic CDWs, their dispersive excitations, and associated electron-phonon anomalies, which are key for understanding the competing electronic instabilities in cuprates.

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Locally commensurate charge-density wave with three-unit-cell periodicity in YBa2Cu3Oy

Nature Communications ◽

10.1038/s41467-021-23140-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Igor Vinograd ◽

Rui Zhou ◽

Michihiro Hirata ◽

Tao Wu ◽

Hadrien Mayaffre ◽

...

Keyword(s):

Charge Density ◽

Cuprate Superconductors ◽

Density Wave ◽

Phase Relationship ◽

Charge Density Waves ◽

X Ray Scattering ◽

Pair Density ◽

Unit Cells ◽

Lock In ◽

Phase Slips

AbstractIn order to identify the mechanism responsible for the formation of charge-density waves (CDW) in cuprate superconductors, it is important to understand which aspects of the CDW’s microscopic structure are generic and which are material-dependent. Here, we show that, at the local scale probed by NMR, long-range CDW order in YBa2Cu3Oy is unidirectional with a commensurate period of three unit cells (λ = 3b), implying that the incommensurability found in X-ray scattering is ensured by phase slips (discommensurations). Furthermore, NMR spectra reveal a predominant oxygen character of the CDW with an out-of-phase relationship between certain lattice sites but no specific signature of a secondary CDW with λ = 6b associated with a putative pair-density wave. These results shed light on universal aspects of the cuprate CDW. In particular, its spatial profile appears to generically result from the interplay between an incommensurate tendency at long length scales, possibly related to properties of the Fermi surface, and local commensuration effects, due to electron-electron interactions or lock-in to the lattice.

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Charge density waves in cuprate superconductors beyond the critical doping

npj Quantum Materials ◽

10.1038/s41535-021-00327-4 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

H. Miao ◽

G. Fabbris ◽

R. J. Koch ◽

D. G. Mazzone ◽

C. S. Nelson ◽

...

Keyword(s):

Charge Density ◽

Cuprate Superconductors ◽

Density Wave ◽

Limited Range ◽

Charge Density Waves ◽

Surface Topology ◽

Superconducting Transition ◽

X Ray Diffraction ◽

Normal State Properties

AbstractThe unconventional normal-state properties of the cuprates are often discussed in terms of emergent electronic order that onsets below a putative critical doping of xc ≈ 0.19. Charge density wave (CDW) correlations represent one such order; however, experimental evidence for such order generally spans a limited range of doping that falls short of the critical value xc, leading to questions regarding its essential relevance. Here, we use X-ray diffraction to demonstrate that CDW correlations in La2−xSrxCuO4 persist up to a doping of at least x = 0.21. The correlations show strong changes through the superconducting transition, but no obvious discontinuity through xc ≈ 0.19, despite changes in Fermi surface topology and electronic transport at this doping. These results demonstrate the interaction between CDWs and superconductivity even in overdoped cuprates and prompt a reconsideration of the role of CDW correlations in the high-temperature cuprate phase diagram.

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Charge density waves and their transitions in anisotropic quantum Hall systems

Communications Physics ◽

10.1038/s42005-021-00613-4 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Yuchi He ◽

Kang Yang ◽

Mark Oliver Goerbig ◽

Roger S. K. Mong

Keyword(s):

Phase Transitions ◽

Charge Density ◽

Density Wave ◽

Quantum Hall ◽

Charge Density Waves ◽

Stripe Phase ◽

Electron Bubble ◽

First Order ◽

Bubble Phase ◽

First Order Phase

AbstractIn recent experiments, external anisotropy has been a useful tool to tune different phases and study their competitions. In this paper, we look at the quantum Hall charge density wave states in the N = 2 Landau level. Without anisotropy, there are two first-order phase transitions between the Wigner crystal, the 2-electron bubble phase, and the stripe phase. By adding mass anisotropy, our analytical and numerical studies show that the 2-electron bubble phase disappears and the stripe phase significantly enlarges its domain in the phase diagram. Meanwhile, a regime of stripe crystals that may be observed experimentally is unveiled after the bubble phase gets out. Upon increase of the anisotropy, the energy of the phases at the transitions becomes progressively smooth as a function of the filling. We conclude that all first-order phase transitions are replaced by continuous phase transitions, providing a possible realisation of continuous quantum crystalline phase transitions.

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Charge Density Waves in YBa2Cu3O6.67 Probed by Resonant X-Ray Scattering under Uniaxial Compression

Physical Review Letters ◽

10.1103/physrevlett.126.037002 ◽

2021 ◽

Vol 126 (3) ◽

Author(s):

H.-H. Kim ◽

E. Lefrançois ◽

K. Kummer ◽

R. Fumagalli ◽

N. B. Brookes ◽

...

Keyword(s):

Charge Density ◽

Uniaxial Compression ◽

Charge Density Waves ◽

Density Waves ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

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X-ray diffraction study of the transient structure of sliding charge density waves in NbSe3

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:20020390 ◽

2002 ◽

Vol 12 (9) ◽

pp. 181-182

Author(s):

H. Requardt ◽

D. Rideau ◽

R. Danneau ◽

A. Ayari ◽

F. Ya Nad ◽

...

Keyword(s):

Charge Density ◽

Density Wave ◽

Charge Density Waves ◽

X Ray Diffraction ◽

X Ray ◽

Slowing Down ◽

Current Contact ◽

Decay Profile ◽

Stretched Exponential Decay ◽

Transient Structure

We present high resolution X-ray diffraction measurements on NbSe3 of the charge-density-wave (CDW) relaxation from the deformation created by the sliding of the CDW. The data are taken in the temperature range 75 K < T < 105 K in the upper-CDW phase of NbSe, and cover spatial positions up to $8OO~\mu$m from the current contact. Convenient fits to the data are obtained by a stretched exponential decay profile yielding exponents μ in the range of 0.4–0.7 and relaxation time-scales τ of the order of 1–150 ms. becoming faster with increasing sample temperature and slowing down with increasing distance from the current contact.

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Energy Scale of the Charge Density Wave in Cuprate Superconductors

Proceedings ◽

10.3390/proceedings2019026020 ◽

2019 ◽

Vol 26 (1) ◽

pp. 20

Author(s):

Sacuto ◽

Loret ◽

Auvray ◽

Civelli ◽

Indranil ◽

...

Keyword(s):

High Temperature ◽

Charge Density ◽

Charge Density Wave ◽

Cuprate Superconductors ◽

High Temperature Superconductors ◽

Density Wave ◽

Energy Scale ◽

Hole Doping ◽

Wide Range

The cuprate high temperature superconductors develop spontaneous charge density wave(CDW) order below a temperature TCDW and over a wide range of hole doping (p). [...]

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Negative differential resistance observed on the charge density wave of a transition metal dichalcogenide

Nanoscale ◽

10.1039/c9nr07857f ◽

2019 ◽

Vol 11 (46) ◽

pp. 22351-22358 ◽

Cited By ~ 1

Author(s):

Adina Luican-Mayer ◽

Yuan Zhang ◽

Andrew DiLullo ◽

Yang Li ◽

Brandon Fisher ◽

...

Keyword(s):

Transition Metal ◽

Charge Density ◽

Voltage Pulse ◽

Negative Differential Resistance ◽

Charge Density Wave ◽

Density Wave ◽

Differential Resistance ◽

Charge Density Waves ◽

Transition Metal Dichalcogenide ◽

Physical Phenomena

Charge density waves and negative differential resistance are seemingly unconnected physical phenomena but they coexist after a voltage pulse manipulation on TaS2 surface with an STM tip.

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Dynamical charge density fluctuations pervading the phase diagram of a Cu-based high-Tc superconductor

Science ◽

10.1126/science.aav1315 ◽

2019 ◽

Vol 365 (6456) ◽

pp. 906-910 ◽

Cited By ~ 35

Author(s):

R. Arpaia ◽

S. Caprara ◽

R. Fumagalli ◽

G. De Vecchi ◽

Y. Y. Peng ◽

...

Keyword(s):

Phase Diagram ◽

Charge Density ◽

Charge Density Waves ◽

Density Fluctuations ◽

Large Area ◽

High Tc ◽

Superconducting Cuprates ◽

X Ray Scattering ◽

Underdoped Region ◽

Dynamical Charge

Charge density modulations have been observed in all families of high–critical temperature (Tc) superconducting cuprates. Although they are consistently found in the underdoped region of the phase diagram and at relatively low temperatures, it is still unclear to what extent they influence the unusual properties of these systems. Using resonant x-ray scattering, we carefully determined the temperature dependence of charge density modulations in YBa2Cu3O7–δ and Nd1+xBa2–xCu3O7–δ for several doping levels. We isolated short-range dynamical charge density fluctuations in addition to the previously known quasi-critical charge density waves. They persist up to well above the pseudogap temperature T*, are characterized by energies of a few milli–electron volts, and pervade a large area of the phase diagram.

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Epitaxial Growth and Charge Density Wave of TaSe2

MRS Proceedings ◽

10.1557/proc-230-231 ◽

1991 ◽

Vol 230 ◽

Cited By ~ 1

Author(s):

Toshihiro Shimada ◽

Fumio S. Ohuchi ◽

Bruce A. Parkinson

Keyword(s):

Transition Metal ◽

Charge Density ◽

Epitaxial Growth ◽

Ultrathin Films ◽

Charge Density Wave ◽

Density Wave ◽

Transition Metal Dichalcogenides ◽

Charge Density Waves ◽

Density Waves ◽

Metal Dichalcogenides

AbstractWe report an epitaxial growth of TaSe2, a family of transition metal dichalcogenides that exhibit Charge Density Waves (CDW). The films that have been characterized with RHEED, LEED, XPS and STM showed two different phases. Occurrence of CDW in the ultrathin films has been detected by XPS and LEED.

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Atomic lattice disorder in charge-density-wave phases of exfoliated dichalcogenides (1T-TaS2)

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1606044113 ◽

2016 ◽

Vol 113 (41) ◽

pp. 11420-11424 ◽

Cited By ~ 45

Author(s):

Robert Hovden ◽

Adam W. Tsen ◽

Pengzi Liu ◽

Benjamin H. Savitzky ◽

Ismail El Baggari ◽

...

Keyword(s):

Charge Density ◽

Density Wave ◽

Transition Metal Dichalcogenides ◽

Charge Density Waves ◽

Periodic Lattice ◽

Atomic Lattice ◽

Scanning Transmission ◽

Out Of Plane ◽

Metal Dichalcogenides ◽

Layered Transition Metal

Charge-density waves (CDWs) and their concomitant periodic lattice distortions (PLDs) govern the electronic properties in several layered transition-metal dichalcogenides. In particular, 1T-TaS2 undergoes a metal-to-insulator phase transition as the PLD becomes commensurate with the crystal lattice. Here we directly image PLDs of the nearly commensurate (NC) and commensurate (C) phases in thin, exfoliated 1T-TaS2 using atomic resolution scanning transmission electron microscopy at room and cryogenic temperature. At low temperatures, we observe commensurate PLD superstructures, suggesting ordering of the CDWs both in- and out-of-plane. In addition, we discover stacking transitions in the atomic lattice that occur via one-bond-length shifts. Interestingly, the NC PLDs exist inside both the stacking domains and their boundaries. Transitions in stacking order are expected to create fractional shifts in the CDW between layers and may be another route to manipulate electronic phases in layered dichalcogenides.

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