标题： 多相超导体PdBi2中的非常规磁化 显示英文标题

标题： Unconventional magnetization in the multiphase superconductor PdBi2

摘要： 非传统超导体在其磁性性质中具有特定的特征，例如在界面和缺陷处的本征磁化以及分数和多量子涡旋，其中大量关注集中在重费米子和高T\_c超导体上。 在这里，我们报告了在候选拓扑超导体$\beta$-PdBi2中观察到的高度异常磁化，这是一种层状材料，其中隐藏的反演对称性破缺导致电子带的自旋极化和自旋-动量锁定。 我们观察到严格线性的、无滞后的直流磁化，当磁场H平行于ab平面时，交流磁化率急剧降低，并且平面内和平面外H之间存在强烈的各向异性。基于我们之前在PdBi2的隧穿谱中发现磁场诱导的从s波到节点p波超导性的相变，我们提出这种异常行为可以通过低H s波相中的常规涡旋结构向对应于超导（节点p波）和正常区域空间相分离的畴结构的转变来解释，从而确定了可能由超导相多重性产生的磁化新特性。 显示英文摘要

摘要： Unconventional superconductors have specific signatures in their magnetic properties, such as intrinsic magnetization at interfaces and around defects and fractional and multiquanta vortices, with much attention focused on heavy fermion and high-T_c superconductors. Here we report an observation of highly anomalous magnetization in a candidate topological superconductor beta-PdBi2, a layered material where hidden inversion symmetry breaking leads to spin polarization and spin-momentum locking of the electronic bands. We observe strictly linear, non-hysteretic dc magnetization, a transition to sharply reduced ac susceptibility vs the magnetic field H applied parallel to the ab plane, and a strong anisotropy between in-plane and out-of-plane H. Based on our earlier finding of a magnetic-field induced phase transition from s-wave to nodal p-wave superconductivity in the tunnelling spectra of PdBi2, we propose that this unusual behavior can be explained by a transition from a conventional vortex structure in low-H s-wave phase to a domain structure corresponding to spatial phase separation into superconducting (nodal p-wave) and normal domains, identifying new features of magnetization that can arise from the multiplicity of superconducting phases.