Researchers from Japan and France managed to detect magnetic fluctuations with pure spin current. This has been done in a much more sensitive way than conventional magnetization measurements.
The researchers used spin glass, a typical frustrated system where a small amount of impurities with magnetic moments is randomly distributed in a nonmagnetic host metal. At high temperatures, the magnetic moments are fluctuating with a very high speed. As the temperature approaches the spin glass temperature (Tg), the fluctuations become slower and then the magnetic moments are frozen at Tg.
In this research, the pure spin current was injected into a spin glass system (CuMnBi alloy). An anomaly was observed far above Tg. This result indicates that pure spin current can detect fluctuating magnetic moments in a much more sensitive way than conventional magnetization measurements.