Artículos de revistas
Charge-density-excitation spectrum in the t-t′-J-V model
Fecha
2017-01Registro en:
Greco, Andres Francisco; Yamase, Hiroyuki; Bejas, Matias Hector; Charge-density-excitation spectrum in the t-t′-J-V model; Physical Soc Japan; Journal Of The Physical Society Of Japan; 86; 3; 1-2017; 1-5
0031-9015
CONICET Digital
CONICET
Autor
Greco, Andres Francisco
Yamase, Hiroyuki
Bejas, Matias Hector
Resumen
We study the density-density correlation function in a large-N scheme of the t-t′-J-V model. When the nearest-neighbor Coulomb interaction V is zero, our model exhibits phase separation in a wide doping region and we obtain large spectral weight near momentum q = (0, 0) at low energy, which originates from the proximity to phase separation. These features are much stronger for electron doping than for hole doping. However, once phase separation is suppressed by including a finite V, the low-energy spectral weight around q = (0, 0) is substantially suppressed. Instead a sharp zero-sound mode is stabilized above the particle-hole continuum. We discuss that the presence of a moderate value of V, which is frequently neglected in the t-J model, is important to understand low-energy charge excitations especially close to q = (0, 0) for electron doping. This insight should be taken into account in a future study of x-ray scattering measurements.