Contactless ultra-high frequency AC-conductivity measurement applicable to destructive magnets above 100 T

The contactless high-frequency electrical conductivity measurement using a “self-resonant” probe coil was performed under the ultra-high magnetic fields generated by the destructive magnets, and applied to measure the upper critical field of the cuprate superconductor La
_1.84
Sr
_0.16
CuO
₄
, and also applied to observe a semiconductor-metal transition of the narrow gap semiconductor FeSi.