Extended Data Fig. 1: The pulses of PSR B2111+46 observed by FAST in the session on 2020-08-24.

The left-most panel is the train of individual pulses for 886 periods, with the mean profile shown in the bottom and the intensity of which is normalized using the peak value. The total energy of every individual pulse is plotted in the immediately right, so that the energy fluctuations are seen very clearly which show the two predominate peaks for both nulling and emission states in the number distributions in the bottom. A segment of the pulse stack is shown in grey for high quality individual pulses, with significant fluctuations of profile amplitude, in which normal individual pulses can be seen in the period No. 702-700, 696 and 680, partial nulling in the period No. 679, and dwarf pulses of the period No. 699 and 682. The detailed polarization profiles for 4 pulses are presented in the right 4 panels, each with total intensity I, linear polarization L and circular polarization V in the bottom subpanel and P A in the upper subpanel. The polarization profiles of the mean pulse are shown in dashed line in these subpanels for comparison. The error bar for PA is ± 1σ.