Coupled spin-charge-phonon fluctuation in the all-in/all-out antiferromagnet Cd2Os2O7

We report on a spin-charge fluctuation in the all-in/all-out pyrochlore magnet Cd2Os2O7, where the spin fluctuation is driven by the conduction of thermally excited electrons/holes and associated fluctuation of Os valence. The fluctuation exhibits an activation energy significantly greater than the spin-charge excitation gap and a peculiar frequency range of 10(6)-10(10) s(-1). These features are attributed to the hopping motion of carriers as small polarons in the insulating phase, where the polaron state is presumably induced by the magnetoelastic coupling via the strong spin-orbit interaction. Such a coupled spin-charge-phonon fluctuation manifests as a part of the metal-insulator transition that is extended over a wide temperature range due to the modest electron correlation comparable with other interactions characteristic for 5d-subshell systems

Neutral Particle Measurement in High Z Plasma in Large Helical Device

In Large Helical Device (LHD), the discharges of high Z are often used in order to obtain high ion temperature. The ion density is relatively smaller than the electron density in high Z plasma. Therefore the high ion temperature can be obtained since the input energy per ion atom is large. In the charge exchange neutral diagnostic, the ion temperature can be obtained by observing the spectra of neutral particles, which are generated by the charge exchange between the background neutral and the plasma ion, and assuming theMaxwellian distribution of the spectra. In calculation, we also consider the charge exchange between the partially ionized high Z ion and proton. The contribution of neutral particle from the charge exchange between argon and proton is small near the center but cannot be neglected near the peripheral region comparing with that of hydrogen charge exchang