Dopant-Bound Spinons in Cu_(1-x)Zn_xGeO_3

TL;DR

This study reveals dopant-bound spinons in Cu_(1-x)Zn_xGeO_3 through polarized light scattering, showing a new mode at half the singlet energy, indicating dopant-induced spinon states.

Contribution

The paper provides experimental evidence for dopant-bound spinons in Cu_(1-x)Zn_xGeO_3 using light scattering techniques, a novel insight into dopant effects in spin-Peierls systems.

Findings

Discovery of a new mode at half the singlet energy in doped samples

Strong evidence for dopant-bound spinons from peak analysis

Doping dependence of the mode's properties

Abstract

Polarized inelastic light scattering experiments on Cu_(1-x)Zn_xGeO_3 (0<= x <= 0.045) single crystals show for x<>0 a new distinct mode at nearly half the energy of the singlet response below the spin-Peierls transition. The temperature, magnetic field, polarization, and doping dependencies of this mode are similar to those of the singlet bound state. The data are interpreted in terms of a spinon-assisted light scattering process. Position and form of the peak provide strong evidence for the presence of dopant-bound spinons in Cu_(1-x)Zn_xGeO_3.