轉載自公眾平臺：npj計算材料學

現代自旋電子器件的發展離不開仿真模擬。由于計算量與模擬的分辨率緊密相關，我們往往會面臨一個困境，即在較慢但準確的方法和較快但不精確的方法之間進行選擇。

現有的微磁動態模擬軟件（如OOMMF），在可接受的計算成本下，可以模擬大尺度、復雜結構的磁相互作用；另一邊，VASP與QUANTUM ESPRESSO等軟件則可以提供原子尺度上的精確計算。

但是介于兩類之間的高精度、大尺度、高速度的微磁模擬依舊是一個空白。此外，在微磁領域里，磁隧道結等原型器件的模擬具有重要意義，將有助于自旋電子器件的設計，但這還處于空白。

來自波蘭AGH理工大學電子研究院的Jakub Mojsiejuk等人，開發了一套開源的、計算效率高的標準化Python包—CMTJ程序，可用于多層自旋電子器件的快速原型化、大規模參數搜索和宏觀自旋模擬。

例如，CMTJ能夠模擬自旋轉移矩理論框架下的電流誘導磁性動力學。此外，作者討論了CMTJ的其他潛在應用與未來擴展方向。該軟件包可為自旋器件的計算模擬提供強大的工具。相關論文近期發布于npj Computational Materials 9: 54 (2023)。

Editorial Summary

Modern development of spintronic devices requires the help of simulations. Because the computational cost is related to the atomic resolution in simulation, we are always facing the dilemma of choosing between a slower, but accurate approach and a faster, but not as precise method. Micromagnetic packages, such as OOMMF, can simulate magnetic interactions of large-scale and complex structures, while maintaining an acceptable computational cost; On the other side, such as VASP and QUANTUM ESPRESSO, will provide precise calculations at the atomic scale. 

However, a high-precision, large-scale and high-speed micromagnetic simulation package between these two types is still a blank. Besides, in the micromagnetic regime, the simulation of prototype devices such as magnetic tunnel junction is of great significance for the design of spintronic devices. 

Jakub Mojsiejuk et. al from Institute of Electronics, AGH University of Science and Technology, Poland, provided an open-source, computationally efficient standardized Python package, CMTJ, for rapid prototyping, large-scale parameter search, and macrospin simulation of multilayer systems. CMTJ is capable of simulating, for example, current-induced magnetization dynamics calculations originating from spin transfer torque. Meanwhile, the authors discussed the other underlying applications and future expansion directions of CMTJ. This software package provides a powerful tool for the simulations of spintronics. This article was recently published in npj Computational Materials 9: 54 (2023).

原文Abstract及其翻譯

CMTJ: Simulation package for analysis of multilayer spintronic devices (CMTJ：用于多層自旋電子器件分析的仿真模擬軟件包)

Jakub Mojsiejuk, S?awomir Zi?tek, Krzysztof Grochot, Witold Skowroński & Tomasz Stobiecki 

Abstract We presentCMTJ—a simulation package for large-scale macrospin analysis of multilayer spintronics devices. Apart from conventional simulations, such as magnetoresistance and magnetisation hysteresis loops, CMTJ implements a mathematical model of dynamic experimental techniques commonly used for spintronics devices characterisation, for instance: spin diode ferromagnetic resonance, pulse-induced microwave magnetometry, or harmonic Hall voltage measurements. We find that macrospin simulations offer a satisfactory level of agreement, demonstrated by a variety of examples. As a unified simulation package, CMTJ aims to accelerate wide-range parameter search in the process of optimising spintronics devices.

摘要我們在此提供了一套仿真模擬軟件包CMTJ，可用于多層自旋電子器件的大規模宏觀自旋分析。除了傳統的磁阻和磁滯回線等模擬，CMTJ還嵌入了一個數學模型，可用于模擬自旋電子學器件測量中用到的動態實驗技術，例如：自旋二極管中的鐵磁共振，脈沖誘導的微波磁學測量，或諧波霍爾電壓測量。通過大量例證，我們認為宏觀自旋模擬能夠提供一個令人滿意的模擬結果。作為一套統一的仿真模擬軟件包，CMTJ旨在加速自旋電子學器件優化過程中的大范圍參數搜索。

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