Increased lifetime of metastable skyrmions by controlled doping
Increased lifetime of metastable skyrmions by controlled doping
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DOI：
10.1103/physrevb.100.014425
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发表时间：
2019-07-22
影响因子：
3.7
通讯作者：
Hatton, P. D.
中科院分区：
文献类型：
--
作者：
Birch, M. T.;Takagi, R.;Hatton, P. D.
以前对亚稳态磁skyrmion的观测表明，接近平衡口袋的亚稳态寿命很短，因此，需要快速冷却才能在低温下产生大量的skyrmion。在这里，我们报告说，亚稳态skyrmions在Cu-2 SeO 3晶体的寿命延长了50倍，只有2.5%的锌掺杂，允许超过50%的人口生存时，场冷却速度仅为1 K/min。我们的系统研究表明，寿命的增强是由于钉扎位点密度的增加，而不是改变衰变过程的能量势垒。我们期望掺杂可以被利用来控制其他手性磁体中的亚稳态SkL状态的寿命，从而提供一种将skyrmion材料工程化以应用于未来设备的方法。
Previous observations of metastable magnetic skyrmions have shown that close to the equilibrium pocket the metastable state has a short lifetime, and therefore, rapid cooling is required to generate a significant skyrmion population at low temperatures. Here, we report that the lifetime of metastable skyrmions in crystals of Cu-2 SeO3 is extended by a factor of 50 with the introduction of only 2.5% zinc doping, allowing over 50% of the population to survive when field cooling at a rate of just 1 K/min. Our systematic study suggests that the lifetime enhancement is due to the increase in the pinning site density, rather than an alteration to the energy barrier of the decay process. We expect that doping can be exploited to control the lifetime of the metastable SkL state in other chiral magnets, offering a method of engineering skyrmion materials towards application in future devices.