Fig. 4: Magnetic field dependences of THz emission.

a The THz emissions at reverse magnetic fields of 0.4 T. The dash line is the reversion of waveform at B = ‒0.4 T. b The THz emissions when a 0.1 T-magnetic field is applied at x-axis and 40^° away from x-axis in xz-plane, respectively. The dash line is the THz waveform under x-directional magnetic field multiplying by cos40^°. c The x- and y-polarization components of the THz emissions with magnetic field B‖x and B‖y. d The amplitude of net magnetic THz signal at time zero as a function of the intensity of magnetic field. Insets in panels (a, b): the schematic illustrations of the corresponding measurements.