True random number generators (TRNGs) have received extensive research owing to their wide applications in information processing, transmission, and encryption. Recently, TRNGs have also been employed in emerging stochastic/probabilistic computing paradigms. TRNGs can be designed based on, for example, oscillator sampling, noise amplifying, and quantum physical effect with the aid of peripheral postprocessing circuitry. With the rapid development of emerging nanoscale devices, such as resistive devices, spintronic devices, and photonic devices, a rich variety of TRNG prototypes have been proposed in the literature. Very recently, skyrmion has emerged as a promising candidate for implementing TRNGs because of the nanometer size and, more importantly, the intrinsic thermal Brownian motion dynamics. In this article, we propose for the first time a TRNG based on the continuous skyrmion thermal Brownian motion in a confined geometry at room temperature. Random bitstream (with equal probability of ~50% for bits “0” and “1”) can be obtained by periodically detecting the relative position of the skyrmion without the need for any additional activations. Furthermore, we implemented a probability-adjustable TRNG, in which a desired probability for bit “0” and bit “1” can be acquired by adding an anisotropy gradient in the device through the voltage-controlled magnetic anisotropy (VCMA) effect. The behaviors of the proposed skyrmion-based TRNGs were studied by using micromagnetic simulations, and the generated random bitstream was tested by the National Institute of Standards and Technology (NIST) suits. Our results demonstrated that the proposed skyrmion-based TRNGs can achieve good randomness with high frequency (>1 GHz) and energy efficiency (< 10 fJ/bit).

中文翻译：

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斯格明子的热布朗运动产生真随机数


真随机数生成器（TRNG）因其在信息处理、传输和加密方面的广泛应用而受到广泛的研究。最近，TRNG 也被用于新兴的随机/概率计算范例。 TRNG 可以基于例如振荡器采样、噪声放大和量子物理效应以及外围后处理电路的帮助来设计。随着电阻器件、自旋电子器件和光子器件等新兴纳米器件的快速发展，文献中提出了丰富多样的TRNG原型。最近，斯格明子因其纳米尺寸以及更重要的是其固有的热布朗运动动力学而成为实现 TRNG 的有前途的候选者。在本文中，我们首次提出了一种基于室温下受限几何结构中连续斯格明子热布朗运动的 TRNG。随机比特流（比特“0”和“1”的概率约为 50%）可以通过定期检测斯格明子的相对位置来获得，而不需要任何额外的激活。此外，我们实现了概率可调的TRNG，其中通过压控磁各向异性（VCMA）效应在器件中添加各向异性梯度，可以获得位“0”和位“1”的期望概率。通过微磁模拟研究了所提出的基于斯格明子的 TRNG 的行为，并由美国国家标准与技术研究所 (NIST) 测试了生成的随机比特流。我们的结果表明，所提出的基于斯格明子的 TRNG 可以在高频 (>1 GHz) 和能源效率 (< 10 fJ/bit) 下实现良好的随机性。