Interaction between spin, lattice, and charge in non-centro\-symmetric correlated metals

这一更新提出在精心选择的非中心对称材料上进行光散射实验，以阐明在复杂磁序存在下的载流子动力学。在实施了几项关键技术创新后，这将完成并扩展在第一个供资期内成功开展的MnSi工作。在MnSi中，声子提供了向磁有序相转变和居里温度以上波动主导范围的相关信息。对称性相关的电子动力学与费米表面的不同薄片有关。在磁有序态中，在拉曼实验中发现的弛豫速率表现出与输运预期的温度依赖性。我们推测电子从复杂的自旋结构中散射，如螺旋或天幕；然而，与纵向或横向运输相反，这没有理论基础。这是更新的目标之一，以澄清有关奇异激发的作用的问题，具有复杂的自旋顺序的材料，如MnSi。为此，我们计划在施加静水压力和电场的条件下对MnSi进行实验。有了手头的设备，我们已经为获得1.46GPa以上的量子无序相做好了最佳准备。这里的电阻率随T^{3/2}变化，这与在磁相中观察到的T^2费米类液体行为有很大的偏差。当施加压力约为1gpa时，skyrmion或a相在相图中扩展最大，对拓扑霍尔效应的影响最大。因此，在拉曼光谱中，我们期望观察到使我们能够推导相关动量依赖载流子性质的特征。我们打算通过Mn0.92Fe0.08Si和Mn0.96Co0.04Si的实验来研究这些基本性质和推测功能之间的相互关系。最后，设想将工作从d-电子系统扩展到f-电子系统，如CePt3Si， CeIrSi3和CeTAl3 (T=Cu, Ag, Au, Pd, Pt)，具有铁磁，反铁磁和超导相。在所有材料类别中，各自的相图将通过在第一个资助期间组装的独特设备获得。在与合作伙伴的密切合作下，我们计划使用互补的实验方法对初等激发进行深入研究。同时理论分析的目的是确定与载流子动力学最相关的相互作用。

This renewal proposes light scattering experiments on carefully selected non-centrosymmetric materials to clarify carrier dynamics in the presence of complex magnetic order. This will complete and extend the work on MnSi that was successfully performed during the first funding period after implementing several crucial technical innovations. In MnSi the phonons were shown to provide relevant information on the transition into the magnetically ordered phase and the fluctuation-dominated range above the Curie temperature. Symmetry-dependent electron dynamics were associated with different sheets of the Fermi surface. In the magnetically ordered state the relaxation rates found in the Raman experiments exhibited a temperature dependence significantly different from that expected from transport. We speculate that the the electrons scatter from complex spin textures such as helices or skyrmions; yet, as opposed to longitudinal or transverse transport, this has no theoretical foundation. It is one of the objectives of the renewal to clarify questions about the role of exotic excitations in materials with complex spin order such as MnSi. To this end we plan experiments on MnSi with applied hydrostatic pressure and field. With the equipment at hand we are optimally prepared to access the quantum disordered phase above 1.46GPa. Here the resistivity varies as T^{3/2}, a significant deviation from the T^2 Fermi liquid-like behavior observed in the helimagnetic phase. With an applied pressure of approximately 1 GPa the skyrmion or A-phase has the largest extension in the phase diagram and the strongest impact on the topological Hall effect. In the Raman spectra we thus expect to observe signatures enabling us to derive related momentum dependent carrier properties. We intend to study the interrelation between these fundamental basic properties and putative functionalities via experiments on Mn0.92Fe0.08Si and Mn0.96Co0.04Si. Finally, it is envisaged to extend the work from d- to f-electron systems such as CePt3Si, CeIrSi3, and CeTAl3 (T=Cu, Ag, Au, Pd, Pt) having ferromagnetic, antiferromagnetic, and superconducting phases in close proximity. In all material classes the respective phase diagrams will be accessible with the unique equipment assembled during the first funding period. In close collaboration with our partners we plan in-depth studies of the elementary excitations using complementary experimental methods. Simultaneous theoretical analysis is intended to identify the interactions which are most relevant for the carrier dynamics.