White-noise quality evaluation in chaotic oscillation of Josephson junction for random-number generation

Recently, a high-quality random-number generator has been highly expected. In obtaining high-quality random-numbers, the use of random physical phenomena is necessary. Among random-number generation methods, we focused on the chaos in a Josephson junction (JJ) under irradiation with a radio frequency (RF). In this study, the chaos in the intrinsic JJ for random-number generation was numerically investigated using the equivalent circuit of the RF-irradiated JJ. In particular, it is important for the random-number generation to obtain a high-quality white-noise output signal. We proposed that the quality of the white noise is quantitatively evaluated using the half-width of the autocorrelation peak. Furthermore, random-numbers were generated from the chaos in the RF-irradiated JJ at high-speed operation than the previous study. The high-quality random-numbers were successfully generated from this chaos, and their quality was verified through statistical verification.