Interplay between topological and thermodynamic stability in a metastable magnetic skyrmion lattice
Interplay between topological and thermodynamic stability in a metastable magnetic skyrmion lattice
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DOI：
10.1038/nphys3506
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发表时间：
2016-01-01
期刊：
影响因子：
19.6
通讯作者：
Kagawa, Fumitaka
中科院分区：
文献类型：
--
作者：
Oike, Hiroshi;Kikkawa, Akiko;Kagawa, Fumitaka
拓扑稳定的物质可以有一个很长的寿命，即使成本昂贵，当热搅动足够低（1，2）。磁性Skyrmion晶格（SkL）代表了一种独特形式的长程磁序，它是拓扑稳定的（3-9），因此可以形成长寿命的亚稳态SkL。然而，在大块晶体中对SkL的实验观察大多局限于有限且狭窄的温度区域，在该温度区域内SkL是热稳定的（5，7，10 -14）;因此，拓扑稳定性的益处仍然不清楚。在这里，我们报告了一个亚稳态的SkL通过淬火一个热稳定的SkL。MnSi的霍尔电阻率测量表明，虽然亚稳态SkL在高温下寿命短，但在低温下寿命延长（>> 1周）。热搅动和拓扑稳定性之间的微妙平衡的操纵使得能够通过利用电加热和随后的快速冷却来确定性地创建/湮灭亚稳态SkL，从而建立了一种控制SkL形成的简便方法。
Topologically stable matter can have a long lifetime, even if thermodynamically costly, when the thermal agitation is sufficiently low(1,2). A magnetic skyrmion lattice (SkL) represents a unique form of long-range magnetic order that is topologically stable(3-9), such that a long-lived, metastable SkL can form. Experimental observations of the SkL in bulk crystals, however, have mostly been limited to a finite and narrow temperature region in which the SkL is thermodynamically stable(5,7,10-14); thus, the benefits of the topological stability remain unclear. Here, we report a metastable SkL created by quenching a thermodynamically stable SkL. Hall-resistivity measurements of MnSi reveal that, although the metastable SkL is short-lived at high temperatures, the lifetime becomes prolonged (>> 1 week) at low temperatures. The manipulation of a delicate balance between thermal agitation and the topological stability enables a deterministic creation/annihilation of the metastable SkL by exploiting electric heating and subsequent rapid cooling, thus establishing a facile method to control the formation of a SkL.