Manifestations of the Electron-Phonon Coupling in the Spectroscopy of High-Temperature Superconductors

Figure 9

Typical OC of different models in two-dimensions and experimental data in weakly doped system: (a) Holstein model at 𝜆=0.44; (b) t-J model at 𝐽=0.3; (c) t-J-H at 𝐽=0.3 and 𝜆=0.39; (d) in-plane OC of doped by 𝑥=1.5% holes Eu1−𝑥Ca𝑥Ba2Cu3O6 at 𝑇=10 K. Theoretical energy scale assumes 𝑡=0.3 eV (1 eV = 8065.5 cm−1). The absolute values of the theoretical 𝜎₁ estimated assuming that hopping distance in plane is 𝑎=3.86 Å and the bulk concentration of holes is 𝑛_ℎ=1.72×10⁻²³ cm−3.

(a)

(b)

(c)

(d)