Ultra-Fast True Random Number Generator Based on Ill-Posedness Nucleation of Skyrmion Bags in Ferrimagnets

An ultra-fast true random number generator (TRNG) based on ill-posedness nucleation of skyrmion bags (sk-bags) with high topological charge (Q) is proposed and studied via numerical method. Under a local spin-polarized current, the ill-posed dynamics of ferrimagnetic spin texture is induced, resulting in the nucleation of sk-bag with high Q (even
$\vert \text{Q}\vert >10$
). Furthermore, in combination with thermal activation, this initially complex phenomenon can be tuned to possess a defined probability distribution of Q. Based on these, we reveal for the first time that the nucleation process of Q, in contrast to the dynamic motion of topological solitons, has the potential to provide an ultra-high true random number generation with a generation rate of 20 Gbit/s, which is the fastest record compared with previous spintronic TRNGs. Finally, we verified the functionality of the device through simulation and demonstrated its advantages in terms of power consumption. Our research provides an additional possibility for developing high-performance TRNG.