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arXiv 2601.03210cond-mat.mes-hallcond-mat.mtrl-sci
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用磁子模拟二维材料

Emulating 2D Materials with Magnons

University of Illinois Urbana-Champaign(伊利诺伊大学厄巴纳-香槟分校)

Bobby Kaman, Jinho Lim, Yingkai Liu, Axel Hoffmann

AI总结:

通过模拟六边形孔排列的晶体,发现其磁子能带结构模仿石墨烯,具有类似蜂窝的特征和若干平带,并能用9带紧束缚哈密顿量解释,为二维材料磁子研究提供了新的实验可及的尺度和控制方法。

摘要:

二维材料中的自旋波(磁子)由于其独特的状态和可调性而受到越来越多的关注。然而,这些系统的许多有趣特性,包括狄拉克点和拓扑态,出现在高频处,而实验探针在此处受到限制。在这里,我们研究了一种由在垂直磁化薄片上排列六边形孔形成的晶体。通过模拟,我们发现磁子能带结构模仿了石墨烯的结构,但还具有一些类似蜂窝的特征,并包含几个平带。令人惊讶的是,其本质可以用一个9带紧束缚哈密顿量来理解。这种对二维材料的明确类比使二维能带工程、拓扑磁子沿一维相界以及在0维缺陷处的光谱隔离模式成为可能。有趣的是,一维相界允许通过磁子类比的量子谷绝缘体访问谷度自由度。这些方法可以扩展到其他磁子系统,但由于模型的简洁性,它可能更具一般性,因为它与电子、声子、光子和冷原子系统中已有的结果相似。这一发现将二维材料中自旋波的物理带到了更实验上可及的尺度,增强了它,并概述了控制磁子态的一些原理。

英文摘要:

Spin waves (magnons) in 2D materials have received increasing interest due to their unique states and potential for tunability. However, many interesting features of these systems, including Dirac points and topological states, occur at high frequencies, where experimental probes are limited. Here, we study a crystal formed by patterning a hexagonal array of holes in a perpendicularly magnetized thin film. Through simulation, we find that the magnonic band structure imitates that of graphene, but additionally has some kagome-like character and includes a few flat bands. Surprisingly, its nature can be understood using a 9-band tight-binding Hamiltonian. This clear analogy to 2D materials enables band-gap engineering in 2D, topological magnons along 1D phase boundaries, and spectrally isolated modes at 0D point defects. Interestingly, the 1D phase boundaries allow access to the valley degree of freedom through a magnonic analog of the quantum valley-Hall insulator. These approaches can be extended to other magnonic systems, but are potentially more general due to the simplicity of the model, which resembles existing results from electron, phonon, photon, and cold atom systems. This finding brings the physics of spin waves in 2D materials to more experimentally accessible scales, augments it, and outlines a few principles for controlling magnonic states.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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