标题： 层状反铁磁中的光开关 显示英文标题

标题： Optical switching in a layered altermagnet

摘要： 反铁磁性无法用传统的共线磁相分类来解释，它通过自旋相关的对称性独特组合、净零磁化以及异常霍尔输运而区别于铁磁性和反铁磁性。 尽管反铁磁态已经在实验中实现，但现有材料的结构刚性和较差的可调性阻碍了它们在功能器件中的集成。 首先，通过钴插入超导的2H-NbSe$_2$多形体，我们诱导并稳定了一个强反铁磁相，并通过理论和实验直接观察到了克雷默斯简并的消除。 随后，利用超快激光脉冲，我们展示了如何淬灭该系统的低温相，实现了第一个光学反铁磁开关的例子。 虽然我们的研究揭示了反铁磁性被忽视的方面，但我们的发现为基于自旋的技术开辟了道路，并为推进新兴的反电子学领域奠定了基础。 显示英文摘要

摘要： Altermagnetism defies conventional classifications of collinear magnetic phases, standing apart from ferromagnetism and antiferromagnetism with its unique combination of spin-dependent symmetries, net-zero magnetization, and anomalous Hall transport. Although altermagnetic states have been realized experimentally, their integration into functional devices has been hindered by the structural rigidity and poor tunability of existing materials. First, through cobalt intercalation of the superconducting 2H-NbSe$_2$ polymorph, we induce and stabilize a robust altermagnetic phase and using both theory and experiment, we directly observe the lifting of Kramers degeneracy. Then, using ultrafast laser pulses, we demonstrate how the low temperature phase of this system can be quenched, realizing the first example of an optical altermagnetic switch. While shedding light on overlooked aspects of altermagnetism, our findings open pathways to spin-based technologies and lay a foundation for advancing the emerging field of altertronics.