Charge-Density-Excitation Spectrum in the t–t′–J–V Model

Greco, Andrés; Yamase, Hiroyuki; Bejas, Matías

doi:10.7566/jpsj.86.034706

Cited by 12 publications

(14 citation statements)

References 38 publications

(78 reference statements)

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“…The origin of the strong intensity has been attributed to [30], La1.875Ba0.125CuO4 [31], and La1.84Sr0.16CuO4 [32], respectively, where we assume J = 132 meV [33]. the proximity to the phase separation from the study of the t-t ′ -J model [27]. Such strong intensity is also seen at x e = 1/12 in Fig.…”

Section: Dynamical Charge Structure Factormentioning

confidence: 82%

Dynamical density matrix renormalization group study of spin and charge excitations in the four-leg t−t′−J ladder

2018

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The ground state of the t-t ′ -J ladder with four legs favors a striped charge distribution for the parameters corresponding to hole-doped cuprate superconductors. We investigate the dynamical spin and charge structure factors of the model by using the dynamical density matrix renormalization group (DMRG) and clarify the influence of the stripe on the structure factors. The dynamical charge structure factor along the momentum direction from q = (0, 0) to (π, 0) clearly shows low-energy excitations corresponding to the stripe order in hole doping. On the other hand, the stripe order weakens in electron doping, resulting in fewer low-energy excitations in the charge channel. In the spin channel, we find incommensurate spin excitations near q = (π, π) forming an hourglass behavior in hole doping, while in electron doping we find clearly spin-wave-like dispersions starting from q = (π, π). Along the (0, 0)-(π, 0) direction, the spin excitations are strongly influenced by the stripes in hole doping, resulting in two branches that form a discontinuous behavior in the dispersion. In contrast, the electron-doped systems show a downward shift in energy toward (π, 0). These behaviors along the (0, 0)-(π, 0) direction are qualitatively similar to momentum-dependent spin excitations recently observed by resonant inelastic x-ray scattering experiments in hole-and electron-doped cuprate superconductors.

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Section: Dynamical Charge Structure Factormentioning

confidence: 82%

Dynamical density matrix renormalization group study of spin and charge excitations in the four-leg t−t′−J ladder

2018

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“…Various approximations to the t-J model 26,40,41 found a strong tendency toward phase separation especially for band parameters appropriate for e-cuprates. The phase separation, however, can be an artifact caused by discarding the Coulomb repulsion 42 . Therefore we included the nearest-neighbor Coulomb interaction in the Hamiltonian (1) to suppress the tendency of the phase separation.…”

Section: Model and Formalismmentioning

confidence: 99%

Doping dependence of d -wave bond-charge excitations in electron-doped cuprates

2019

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Motivated by the recent experiments reporting the doping dependence of the short-range charge order (CO) in electron-doped cuprates, we study the resonant x-ray scattering spectrum from dwave bond-charge fluctuations obtained in the two-dimensional t-J model. We find that (i) the CO is short-range, (ii) the CO peak is pronounced at low temperature, (iii) the peak intensity increases with decreasing carrier doping δ down to δ ≈ 0.10 and is substantially suppressed below δ ≈ 0.10 due to strong damping, and (iv) the momentum of the CO decreases monotonically down to δ ≈ 0.10 and goes up below δ ≈ 0.10. These results reasonably capture the major features of the experimental data, and the observed short-range CO can be consistently explained in terms of bond-charge fluctuations with an internal d-wave symmetry. PACS numbers:Recently resonant x-ray scattering (RXS), resonant inelastic x-ray scattering (RIXS), and high-energy x-ray scattering revealed the presence of short-range charge order (CO) with modulation vector along the axial direction (0, 0)-(π, 0) in various hole-doped cuprates (h-cuprates) such as Y-1-5 , Bi-6-9 , and Hg-based 10,11 compounds, implying that the CO can be a universal phenomenon in h-cuprates. The understanding of the origin of those charge correlations, therefore, will likely yield an important clue to the origin of the pseudogap as well as high-T c superconductivity 12 . In fact, a large number of theoretical studies were performed 13-22 , although a consensus has not been obtained.On the other hand, a short-range CO was also observed in electron-doped cuprates [23][24][25] (e-cuprates). Since the pseudogap features similar to those in h-cuprates are much weaker in e-cuprates, a theoretical study may be less complicated in e-cuprates. However, compared to theoretical studies of h-cuprates 13-22 , the CO in e-cuprates is much less studied [26][27][28][29] . Ref. 26 showed a comprehensive study of all possible COs in the two-dimensional (2D) t-J model and found a strong tendency to d-wave bond-charge order 30 . Ref. 27 then showed that d-wave bond-charge fluctuations can capture the charge excitation spectrum observed in experiments 23 . Although the theoretical framework is different from Refs. 26 and 27, similar d-wave bond-charge fluctuations were also proposed in Ref. 28 to explain the experimental data.The d-wave bond-charge order is different from a usual textbook-like charge-densitywave because the bond charge has an internal structure characterized by a d-wave symmetry.Therefore if the short-range CO observed in e-cuprates is indeed a d-wave bond-charge order, it can be interpreted as the first observation of unconventional CO in e-cuprates. Given that d-wave bond-charge order was discussed in h-cuprates 31 , it can be a universal phenomenon in the whole cuprate family. In addition, d-wave bond-charge order would be reduced to the electronic nematic order 32 , more precisely a d-wave Pomeranchuk instability 33-35 when the momentum transfer approaches zero. In this sense, the nematic ph...

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“…The charge excitation spectrum for V 2 = 0 and t z = 0 was already shown in Ref. [56], where the zero-sound mode is realized as collective excitations, which are gapless at q = (0, 0, q z ) independent of q z . In the present layered model with a finite t z , the zero-sound mode acquires a gap at q = (0, 0, q z ) for q z = 0 but remains gapless for q z = 0; see Ref.…”

Section: G Absence Of Long-range Coulomb Interactionmentioning

confidence: 54%

“…the charge excitations are characterized by a zero-sound mode around q = (0, 0, q z ) (see Ref. [56]), which becomes gapless at q = (0, 0, 0). In this case, an emergent band corresponding to that around ω/t ≈ 1 tends to merge into the main quasiparticle band (see Fig.…”

Section: H H H H Hmentioning

confidence: 99%

Electron self-energy from quantum charge fluctuations in the layered t−J model with long-range Coulomb interaction

2021

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Employing a large-N scheme of the layered t-J model with the long-range Coulomb interaction, which captures the fine details of the charge excitation spectra recently observed in cuprate superconductors, we explore the role of charge fluctuations on the electron self-energy. We fix the temperature at zero and focus on quantum charge fluctuations. We find a pronounced asymmetry of the imaginary part of the self-energy Im (k, ω) with respect to ω = 0, which is driven by strong electron correlation effects. The quasiparticle weight is reduced dramatically, which occurs almost isotropically along the Fermi surface. Concomitantly, an incoherent band and a sharp side band are generated and acquire sizable spectral weight. All these features are driven by the usual on-site charge fluctuations, which are realized in a rather high-energy region and yield plasmon excitations. On the other hand, the low-energy region with the scale of the superexchange interaction J is dominated by bond-charge fluctuations. Surprisingly, compared with the effect of on-site charge fluctuations, their effect on the electron self-energy is much weaker, even if the system approaches close to bond-charge instabilities. Furthermore, quantum charge dynamics does not produce a clear kink nor a pseudogap in the electron dispersion.

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Charge-Density-Excitation Spectrum in the t–t′–J–V Model

Cited by 12 publications

References 38 publications

Dynamical density matrix renormalization group study of spin and charge excitations in the four-leg t−t′−J ladder

Dynamical density matrix renormalization group study of spin and charge excitations in the four-leg t−t′−J ladder

Doping dependence of d -wave bond-charge excitations in electron-doped cuprates

Electron self-energy from quantum charge fluctuations in the layered t−J model with long-range Coulomb interaction

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