Size dependence of the skyrmions arrangements of the FeGe nanostrip in panel (a) and nanodisk in panel (b). The measured temperature was 220 K and a magnetic field was applied to stabilize the skyrmion state. W and R represent the width of the nanostrip and the diameter of nanodisk, respectively. The red numbers in panel (a) and panel (b) stand for the number of skyrmion chain and number of isolated skyrmions, respectively.^[11,22]