学术活动
量子材料
A theory of skyrmion crystal formation
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主讲人: 王向荣(香港科技大学)
地点: 腾讯会议 ID: 402 444 586
时间: 时间: 2021年11月10日 (周三)下午3:30
主持 联系人: 韩伟<weihan@pku.edu.cn>
主讲人简介: 王向荣,香港科技大学终身教授;1984年毕业于武汉大学物理系;1990年在美国罗彻斯特大学(University of Rochester)获博士学位。
研究方向:凝聚态理论,目前研究领域包括自旋电子学,拓扑态及其动力学,金属-绝缘体相变,及非线性动力学。

摘要:

In this talk, I will first review our current understanding of skyrmion crystal formation. Then I will present a generic theory about skyrmion crystal (SkX) formation and the fascinating thermodynamic behaviours in chiral magnetic thin films. We will see that a chiral magnetic film can have many metastable states with an arbitrary skyrmion density up to a maximal value when a parameter k measuring the relative Dzyaloshinskii-Moriya interaction (DMI) strength is large enough. We will explain why a film prefers a stripy state, such as a helical state, at a low field, and an SkX around an optimal field when k is above a critical value. Decrease of k value explains why SkXs become metastable at low temperature in most skyrmion systems.