Magnetic excitations in La-based cuprate superconductors: slave-boson mean-field analysis of the two-dimensional t-J model

Abstract

Motivated by recent inelastic neutron scattering experiments up to a high-energy region for La-based cuprates, we compute (q,omega) maps of the imaginary part of the dynamical magnetic susceptibility chi(q,omega) in the slave-boson mean-field approximation to the two-dimensional t-J model. While the strong spectral weight appears at incommensurate positions, namely at q neq Q =(pi,pi), for low energy, the incommensurate signals disperse with increasing omega and finally merge into a commensurate signal at a particular energy omega=omega_Q. These features are seen in both the d-wave pairing state and the normal state. In particular, the incommensurate signals below omega_Q in the normal state are due to the Fermi surface geometry, which we expect for La-based cuprates because of a tendency to d-wave type Fermi surface deformations. Above omega_Q, strong signals appear to trace an upward dispersion especially for a low doping rate in the d-wave pairing state while typically broad spectral weight is obtained around q=Q in the normal state. Salient features of magnetic excitations in La-based cuprates are thus naturally captured in terms of particle-hole excitations. Global understanding of magnetic excitations in high-Tc cuprates is discussed through a comparison with magnetic excitations in YBa_2Cu_3O_y.

22 pages, 5 figures

References in corpus (8)

• Instability toward Formation of Quasi-One-Dimensional Fermi Surface in Two-Dimensional t-J Model
• Possible Quasi-One-Dimensional Fermi Surface in La_{2-x}Sr_{x}CuO_4
• Resonant magnetic excitations at high energy in superconducting $\mathbf{YB}{\mathbf{a}}_2\mathbf{C}{\mathbf{u}}_3{\mathbf{O}}_{6.85}$
• Magnetic excitations in a bond-centered stripe phase: Spin waves far from the semi-classical limit
• Magnetic excitations and their anisotropy in YBCO: slave-boson mean-field analysis of bilayer t-J model
• Spontaneous breaking of the Fermi surface symmetry in the t-J model: a numerical study
• Magnetic Excitation of t-J Model with Quasi-One-Dimensional Fermi Surface -- Possible Relevance to LSCO Systems
• Double dispersion of the magnetic resonant mode in cuprates

Cited by in corpus (11)

• Lattice symmetry breaking in cuprate superconductors: Stripes, nematics, and superconductivity
• Fluctuating Stripes in Strongly Correlated Electron Systems and the Nematic-Smectic Quantum Phase Transition
• Fermi Liquid instabilities in two-dimensional lattice models
• Generalized Pomeranchuk instabilities in graphene
• Spin susceptibility in bilayered cuprates: resonant magnetic excitations
• Fermi surface in La-based cuprate superconductors from Compton scattering imaging
• Theoretical insights into electronic nematic order, bond-charge orders, and plasmons in cuprate superconductors
• Phenomenological theory of spin excitations in La- and Y-based cuprates
• Spin and bond-charge excitation spectra in correlated electron systems near antiferromagnetic phase
• Cuprate Superconductors in the Vicinity of a Pomeranchuk Instability
• Beyond on-site Hubbard interaction in charge dynamics of cuprate superconductors