TY - JOUR
T1 - Spinon confinement and a sharp longitudinal mode in Yb 2 Pt 2 Pb in magnetic fields
AU - Gannon, W. J.
AU - Zaliznyak, I. A.
AU - Wu, L. S.
AU - Feiguin, A. E.
AU - Tsvelik, A. M.
AU - Demmel, F.
AU - Qiu, Y.
AU - Copley, J. R.D.
AU - Kim, M. S.
AU - Aronson, M. C.
N1 - Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - 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.
AB - 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.
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U2 - 10.1038/s41467-019-08715-y
DO - 10.1038/s41467-019-08715-y
M3 - Article
C2 - 30850591
AN - SCOPUS:85062642611
SN - 2041-1723
VL - 10
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 1123
ER -