2019/03/08 by W. J. Gannon, I. A. Zaliznyak, L. S. Wu +7 · 2 citations
Physics and Astronomy · #Antiferromagnetism #Density matrix renormalization group #Excitation #Ground state #Magnetic field #Physics of Superconductivity and Magnetism #Quantum dot #Quasiparticle #Rare-earth and actinide compounds #Spin (aerodynamics) #Spinon #Topological Materials and Phenomena #cond-mat.str-el
paper · pdf · doi:10.1038/s41467-019-08715-y
published as Nature Communications 10, 1123 (2019)
openalex publication_date 2019/03/08 · openalex created_date 2019/03/22 · arxiv created 2019/07/01 · arxiv updated 2019/07/10 · openalex updated_date 2026/08/06
Abstract The fundamental excitations in an antiferromagnetic chain of spins-1/2 are spinons, de-confined fractional quasiparticles that when combined in pairs, form a triplet excitation continuum. In an Ising-like spin chain the continuum is gapped and the ground state is Néel ordered. Here, we report high resolution neutron scattering experiments, which reveal how a magnetic field closes this gap and drives the spin chains in Yb 2 Pt 2 Pb to a critical, disordered Luttinger-liquid state. In Yb 2 Pt 2 Pb the effective spins-1/2 describe the dynamics of large, Ising-like Yb magnetic moments, ensuring that the measured excitations are exclusively longitudinal, which we find to be well described by time-dependent density matrix renormalization group calculations. The inter-chain coupling leads to the confinement of spinons, a condensed matter analog of quark confinement in quantum chromodynamics. Insensitive to transverse fluctuations, our measurements show how a gapless, dispersive longitudinal mode arises from confinement and evolves with magnetic order.