Fig. 7: Demonstration of a two-bit random number generator.
From: Néel domain walls with bistable chirality in a perpendicularly magnetized ferrimagnetic insulator
a Examples of two-bit states represented by the DW motion direction on two DW tracks. Each image is obtained from the difference between the image taken before and after a creep current pulse. The red crosses mark the horizontal and vertical position of a DW track. Black in the boxed area represents a successful switching of DW chirality by \({H}_{x}^{{{\rm{sw}}}}\) encoded as 1, whereas white indicates that the DW chirality remains the same as that set by the field pulse, \({H}_{x}^{{{\rm{set}}}}\), encoded as 0. The four images shown therefore represent 00, 01, 10, and 11, respectively, as labeled next to each image. b Histogram for each two-bit state.
