Fractionalization, entanglement, and separation: understanding the collective excitations in a spin-orbital chain

Abstract

Using a combined analytical and numerical approach, we study the collective spin and orbital excitations in a spin-orbital chain under a crystal field. Irrespective of the crystal field strength, these excitations can be universally described by fractionalized fermions. The fractionalization phenomenon persists and contrasts strikingly with the case of a spin chain, where fractionalized spinons cannot be individually observed but confined to form magnons in a strong magnetic field. In the spin-orbital chain, each of the fractional quasiparticles carries both spin and orbital quantum numbers, and the two variables are always entangled in the collective excitations. Our result further shows that the recently reported separation phenomenon occurs when crystal fields fully polarize the orbital degrees of freedom. In this case, however, the spinon and orbiton dynamics are decoupled solely because of a redefinition of the spin and orbital quantum numbers.

Original: 9 pages, 9 figures (including supplementary material); a slightly revised version w.r.t. v2 (conclusions unchanged). Revised: the manuscript (v4) is accepted for publication in Physical Review B on March 20, 2015

References in corpus (11)

• Spin-Orbital Separation in the quasi 1D Mott-insulator Sr2CuO3
• Variational cluster approach to correlated electron systems in low dimensions
• Fingerprints of spin-orbital entanglement in transition metal oxides
• Entropy dependence of correlations in one-dimensional SU(N) antiferromagnets
• Adiabatic loading of one-dimensional SU(N) alkaline earth fermions in optical lattices
• Entanglement Entropy and Spectra of the One-dimensional Kugel-Khomskii Model
• Von Neumann Entropy Spectra and Entangled Excitations in Spin-Orbital Models
• Spin-Orbital Entanglement and Phase Diagram of Spin-orbital Chain with $SU(2)\times SU(2)$ Symmetry
• Topological Order in an Entangled SU(2)$\otimes$XY Spin-Orbital Ring
• Spin-Dynamics of the antiferromagnetic S=1/2-Chain at finite magnetic Fields and intermediate Temperatures
• Charge and Spin Fractionalization Beyond the Luttinger Liquid Paradigm

Cited by in corpus (21)

• Probing light-driven quantum materials with ultrafast resonant inelastic X-ray scattering
• Fingerprints of an Exotic Orbital-Selective Mott Phase in the Block Magnetic State of BaFe${}_2$Se${}_3$ Ladders
• Variational tensor network renormalization in imaginary time: Two-dimensional quantum compass model at finite temperature
• Quantum phase transitions in a generalized compass chain with three-site interactions
• Numerically exploring the 1D-2D dimensional crossover on spin dynamics in the doped Hubbard model
• Numerical Investigation of Spin Excitations in a Doped Spin Chain
• How spin-orbital entanglement depends on the spin-orbit coupling in a Mott insulator
• Spin-orbital order in undoped manganite LaMnO3 at finite temperature
• Quantum entanglement in the one-dimensional spin-orbital SU(2)$\otimes XXZ$ model
• Entanglement Driven Phase Transitions in Spin-Orbital Models
• Green's function variational approach to orbital polarons in KCuF3
• Orbiton-magnon interplay in the spin-orbital polarons of KCuF3 and LaMnO3
• Pairwise entanglement and the Mott transition for correlated electrons in nanochains
• Excitonic density-waves, bi-excitons and orbital selective pairing in two-orbital correlated chains
• Exciton and light induced ferromagnetism from doping a moiré Mott insulator
• One- and two-particle correlation functions in the cluster perturbation theory for cuprates
• Spinon-orbiton repulsion and attraction mediated by Hund's rule
• Excitonic wave-packet evolution in a two-orbital Hubbard model chain: A real-time real-space study
• Evolution of Spin-Orbital Entanglement with Increasing Ising Spin-Orbit Coupling
• One-dimensional frustrated plaquette compass model: Nematic phase and spontaneous multimerization
• Orbital liquid in the $e_g$ orbital Hubbard model in $d=\infty$ dimensions