Observation of E8 Particles in an Ising Chain Antiferromagnet

Abstract

Near the transverse-field induced quantum critical point of the Ising chain, an exotic dynamic spectrum consisting of exactly eight particles was predicted, which is uniquely described by an emergent quantum integrable field theory with the symmetry of the $E_8$ Lie algebra, but rarely explored experimentally. Here we use high-resolution terahertz spectroscopy to resolve quantum spin dynamics of the quasi-one-dimensional Ising antiferromagnet BaCo${}_2$V${}_2$O${}_8$ in an applied transverse field. By comparing to an analytical calculation of the dynamical spin correlations, we identify $E_8$ particles as well as their two-particle excitations.

6 pages, 3 figures, plus supplementary materials

References in corpus (4)

• Quantum Simulation of Antiferromagnetic Spin Chains in an Optical Lattice
• Bose-Einstein Condensation in Magnetic Insulators
• Spinon Confinement in the One-Dimensional Ising-Like Antiferromagnet SrCo2V2O8
• Finite temperature spin dynamics in a perturbed quantum critical Ising chain with an $E_8$ symmetry

Cited by in corpus (4)

• Experimental Observation of Quantum Many-Body Excitations of $E_8$ Symmetry in the Ising Chain Ferromagnet CoNb${}_2$O${}_6$
• Magnetic excitations in the one-dimensional Heisenberg-Ising model with external fields and their experimental realizations
• Field-induced antiferromagnetism and Tomonaga-Luttinger liquid behavior in the quasi-one-dimensional Ising-Antiferromagnet SrCo2V2O8
• From Complexification to Self-Similarity: New Aspects of Quantum Criticality