Effect of strain-induced orbital splitting on the magnetic excitations in undoped cuprates

Abstract

We investigate the magnetic excitations in view of the recent reports suggesting that the spin-wave energy may exhibit a significant dependence on the in-plane strain of a thin film of La${}_2$CuO${}_4$. The nature of dependence, as we find, can be explained naturally within a two-orbital model based on the $d_{x^2-y^2}$ and $d_{3z^2-r^2}$ orbitals. In particular, as the orbital-splitting energy between the $d_{x^2-y^2}$ and $d_{3z^2-r^2}$ orbitals increases with compressive strain, the zone-boundary spin-wave energy hardens. However, the hardening persists only until the orbital splitting reaches $\sim$ 2eV, beyond which there is no significant change. The behavior of zone-boundary spin-wave energy is explained in terms of the extent of hybridization between one of the exchange-split $d_{x^2-y^2}$ band which is nearly half filled and the $d_{3z^2-r^2}$ band. The role of second-order antiferromagnetic superexchange process involving the inter-orbital hopping is also discussed.

6 pages, 5 figures

References in corpus (12)

• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Anomalous High-Energy Spin Excitations in La2CuO4
• Two-Orbital Model Explains the Higher Transition Temperature of the Single-Layer Hg-Cuprate Superconductor Compared to That of the La-Cuprate Superconductor
• Spin excitations in a single La${}_2$CuO${}_4$ layer
• Observation of a 500meV Collective Mode in La${}_{2-x}$Sr${}_x$CuO${}_4$ and Nd${}_2$CuO${}_4$
• Low energy theory of the t-t'-t''-U Hubbard Model at half-filling: interaction strengths in cuprate superconductors and an effective spin-only description of La_2CuO_4
• Realistic many-body models for Manganese Monoxide under pressure
• Effective Coulomb interactions in solids under pressure
• Band Structure of Overdoped Cuprate Superconductors: Density Functional Theory Matching Experiments
• Spin excitations in the nematic phase and the metallic stripe spin-density wave phase of iron pnictides
• Revealing the Coulomb interaction strength in a cuprate superconductor
• Spin-charge coupling in a band ferromagnet: magnon-energy reduction, anomalous softening, and damping

Cited by in corpus (1)

• Exact results for the Hubbard model on bipartite lattices in spatial dimensions $d>1$: Seven theorems from the full [SU(2)$\times$SU(2)$\times$U(1)]/${\mathbb{Z}}_2^2$ symmetry