Spinon confinement and a sharp longitudinal mode in Yb2Pt2Pb in magnetic fields.
W J GannonIgor A ZaliznyakL S WuA E FeiguinA M TsvelikFranz DemmelY QiuJ R D CopleyM S KimM C AronsonPublished in: Nature communications (2019)
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 Yb2Pt2Pb to a critical, disordered Luttinger-liquid state. In Yb2Pt2Pb 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.
Keyphrases
- energy transfer
- heavy metals
- molecularly imprinted
- density functional theory
- room temperature
- high resolution
- quantum dots
- ionic liquid
- cross sectional
- molecular dynamics
- solid phase extraction
- aqueous solution
- gene expression
- molecular dynamics simulations
- genome wide
- risk assessment
- mass spectrometry
- single cell
- dna methylation
- transition metal
- tandem mass spectrometry
- high speed