评论：关于“用安德烈夫反射探测交替磁体CrSb中动量相关的自旋极化”
Comment on "Andreev Reflection to Probe Momentum-Dependent Spin Polarization in Altermagnet CrSb"
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中文总结 AI 辅助
本文评论指出Zhang等人关于CrSb中安德烈夫自旋极化的测量因对称性禁止而无效，仅一个方向允许约50%的极化，其报道的大值源于错误定义和拟合缺陷。
中文摘要 AI 辅助
Zhang等人[Phys. Rev. Lett. 137, 016701 (2026)]报道了通过沿(0001)、(-1-120)和(10-10)方向的点接触安德烈夫反射在交替磁体CrSb中观测到的动量相关自旋极化。我们证明他们声称测得的安德烈夫自旋极化被对称性所禁止：在扩散区，CrSb中所有方向的自旋极化都恒为零；在弹道区，所测三个方向中有两个方向的自旋极化也为零。仅在一个方向上允许非零值，而根据计算的能带结构，该值约为50%。所报道的较大且近乎各向同性的值源于对弹道安德烈夫自旋极化的错误定义，该定义在固定三维动量下评估自旋不对称性；安德烈夫选择定则仅在与界面平行的动量分量上具有局域性。此外，弹道区未被证实，且拟合过程存在缺陷。
英文摘要
Zhang et al. [Phys. Rev. Lett. 137, 016701 (2026)] report momentum-dependent spin polarization in the altermagnet CrSb from point-contact Andreev reflection along the (0001), (-1-120), and (10-10) directions. We show that the Andreev spin polarization they claim to measure is forbidden by symmetry: it vanishes identically in the diffusive regime for all directions in CrSb, and in the ballistic regime for two of the three orientations measured. It is allowed only along one direction, where the calculated band structure gives ~50%. The large, nearly isotropic values reported follow from an incorrect definition of ballistic Andreev spin polarization that evaluates the spin asymmetry at fixed three-dimensional momentum; the Andreev selection rule is local only in the momentum component parallel to the interface. Moreover, the ballistic regime is not demonstrated, and the fitting procedure is flawed.
发表机构
- George Mason University（乔治梅森大学）
- Hebrew University of Jerusalem（耶路撒冷希伯来大学）
- Wayne State University（韦恩州立大学）
机构由 AI 辅助整理，请以论文原文为准。
