Field-dependent real part of the optical conductivity σ 1 ( ω ) of the 385-μm-thick TbInO 3 crystal for various external magnetic field configurations and temperatures. k THz ⊥ H EXT ∥ B THz at 1.5 K. The directions of the propagation wavevector k THz , the terahertz electric field E THz , the terahertz magnetic field B THz and the external magnetic field H EXT are shown in the right lower corners. In a , the room-temperature optical conductivity is almost unchanged under an external magnetic field of up to 7 T. The room-temperature optical conductivity acquired in the absence of an external magnetic field is also plotted as a grey filled curve in b – d . CFTs observed at 1.5 K show varied dependences under an external magnetic field.
