Development of techniques for the dielectric constant measurement in matter in ultrahigh magnetic fields exceeding 100 T

We present a development of the dielectric constant (ɛ) measurement technique in ultrahigh magnetic fields using radio frequency (RF) modulation. The ultrahigh magnetic fields exceeding 100 T are generated by the single-turn coil (STC) technique. The RF frequency range is from 30 to 50 MHz, which is high enough for the STC with a field duration of several microseconds. We applied the developed technique to a prototypical ferroelectric material BaTiO3. The ɛ at near the ferroelectric transition temperature has been found to decrease when the magnetic field is higher than around 100 T. The absence of the magnetic field variation in ɛ in the paraelectric phase at a higher temperature suggests that ferroelectricity in BaTiO3 is significantly affected by an ultrahigh magnetic field.