AI 中文总结
该研究将非线性磁化率χ⁽¹⁾用于切换完全补偿反铁磁体的时间反演伴侣，提出计算χ⁽¹⁾的第一性原理形式并应用于Mn₃XN系列，揭示其温度依赖性，提供通用切换方案。
AI 中文摘要
近年来，反铁磁体（AFM）受到了广泛关注，因为在许多材料中发现了大量与时间反演对称性（TRS）破缺相关的非平凡、技术上相关的性质。然而，除了少数具有非零净磁化强度的情况外，通常难以确定性地选择AFM态的时间反演（TR）伴侣。最近，研究表明，在HoAgGe中具有严格零净磁化强度的kagome自旋冰基态的TR伴侣可以通过非线性磁化率χ⁽¹⁾来选择。在这项工作中，我们将这一情景推广到一大类具有零净磁化强度但可通过χ⁽¹⁾进行场切换的基态的手性AFM。在对χ⁽¹⁾及其对称性约束进行一般性讨论后，我们首先提出了一种计算χ⁽¹⁾的第一性原理形式，包括平均场和自洽修正，然后将该方法应用于Γ₅g相中的非共线AFM家族Mn₃XN（X=Ni、Ag、Ga、Zn、Sn）。使用3子晶格玩具模型说明了类似非共线AFM中χ⁽¹⁾起源的直观图像，该模型还预测了由于纵向和横向单自旋磁化率之间的竞争导致的χ⁽¹⁾的非平凡温度依赖性。我们的工作表明，非线性磁化率可以作为访问和切换完全补偿AFM中TR伴侣的通用方案。
英文摘要
Antiferromagnets (AFM) have attracted considerable attention in recent years because a number of nontrivial, technologically relevant properties associated with time-reversal symmetry (TRS) breaking are discovered in many materials. However, time-reversal (TR) partners of AFM states are generally challenging to be selected deterministically except in a few cases with nonzero net magnetization. Recently, it has been shown that the TR partners of the kagome spin ice ground state in HoAgGe with strictly zero net magnetization can be selected through a nonlinear magnetic susceptibility $χ^{(1)}$. In this work, we generalize this scenario to a broad class of chiral AFM with zero net magnetization but field-switchable ground states through $χ^{(1)}$. After a general discussion of $χ^{(1)}$ and its symmetry constraints, we first present a first-principles formalism for calculating it including both mean-field and self-consistent corrections, and then apply the approach to the noncollinear AFM family Mn$_3X$N ($X=$ Ni, Ag, Ga, Zn, Sn) in the $Γ_{5g}$ phase. An intuitive picture of the origin of $χ^{(1)}$ in similar noncollinear AFM is illustrated using 3-sublattice toy model. The model also predicts a nontrivial temperature dependence of $χ^{(1)}$ due to competitions between the longitudinal and transverse single-spin susceptibilities. Our work shows that nonlinear susceptibility can serve as a general protocol for accessing and switching TR partners in fully compensated AFM.
Comments9 pages; supplemental material included in /anc
