Subnanosecond Fluctuations in Low-Barrier Nanomagnets
Subnanosecond Fluctuations in Low-Barrier Nanomagnets
复制标题
低势垒纳米磁体中的亚纳秒涨落
DOI：
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发表时间：
2019
影响因子：
4.6
通讯作者：
P. Upadhyaya
中科院分区：
文献类型：
--
作者：
J. Kaiser;A. Rustagi;Kerem Y Çamsarı;Jonathan Z. Sun;S. Datta;P. Upadhyaya
由于热转矩产生的快速磁涨落具有从密码学到概率计算等有用的技术功能。到目前为止所研究的典型单轴各向异性磁体中涨落的特征时间受众所周知的能量弛豫机制的下限约束。这个时间与\(\alpha^{-1}\)成正比，其中\(\alpha\)是耗散过程强度的参数。在此，我们从理论上分析了易平面和反铁磁耦合纳米磁体中的涨落动力学。我们发现，在此类磁体中，动力学受到涨落内禀场的强烈影响，这产生了一种额外的退相类型机制来消除相关性。特别是，我们确定了两个用于表征涨落的时间尺度：（i）纳米磁体反转的平均时间——对于实验相关的低阻尼区域，它主要由退相决定，并且与\(\alpha\)无关；（ii）单个纳米磁体记忆丧失的时间尺度——它与\(\alpha^{-1/3}\)成正比，并且由能量耗散和退相机制共同决定。对于内禀场的典型实验可获取值，与单轴磁体中仅由能量弛豫机制设定的界限相比，由此产生的热涨落速率提高了多个数量级。这可能会提高利用磁涨落的新兴器件的运行速度。
Fast magnetic fluctuations due to thermal torques have useful technological functionality ranging from cryptography to probabilistic computing. The characteristic time of fluctuations in typical uniaxial anisotropy magnets studied so far is bounded from below by the well-known energy relaxation mechanism. This time scales as $alpha^{-1}$, where $alpha$ parameterizes the strength of dissipative processes. Here, we theoretically analyze the fluctuating dynamics in easy-plane and antiferromagnetically coupled nanomagnets. We find in such magnets, the dynamics are strongly influenced by fluctuating intrinsic fields, which give rise to an additional dephasing-type mechanism for washing out correlations. In particular, we establish two time scales for characterizing fluctuations (i) the average time for a nanomagnet to reverse|which for the experimentally relevant regime of low damping is governed primarily by dephasing and becomes independent of $alpha$, (ii) the time scale for memory loss of a single nanomagnet|which scales as $alpha^{-1/3}$ and is governed by a combination of energy dissipation and dephasing mechanism. For typical experimentally accessible values of intrinsic fields, the resultant thermal-fluctuation rate is increased by multiple orders of magnitude when compared with the bound set solely by the energy relaxation mechanism in uniaxial magnets. This could lead to higher operating speeds of emerging devices exploiting magnetic fluctuations.
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通过磁体隧道结的电报开关信号，用于具有高信息容量的神经尖峰信号
影响因子：
3.2
作者：
Zink, Brandon R.;Lv, Yang;Wang, Jian-Ping
通讯作者：
Wang, Jian-Ping
影响因子：
1.2
作者：
Hassan, Orchi;Faria, Rafatul;Datta, Supriyo
通讯作者：
Datta, Supriyo
DOI：
10.1049/iet-cdt.2017.0145
发表时间：
2018-02
期刊：
IET Comput. Digit. Tech.
影响因子：
--
作者：
Steven D. Pyle;Kerem Y Çamsarı;R. Demara
通讯作者：
Steven D. Pyle;Kerem Y Çamsarı;R. Demara
影响因子：
1.6
作者：
Brad Parks;M. Bapna;Julianne Igbokwe;H. Almasi;Weigang Wang;S. Majetich
通讯作者：
Brad Parks;M. Bapna;Julianne Igbokwe;H. Almasi;Weigang Wang;S. Majetich
影响因子：
44.1
作者：
Baltz, V.;Manchon, A.;Tserkovnyak, Y.
通讯作者：
Tserkovnyak, Y.