For nearly a century, the Stoner model has dominated research in itinerant ferromagnetism, yet recent work on ultracold, optically trapped Fermi gases suggests that phase separation of spins occurs independent of long-range magnetic order. In this paper, we consider the breakdown of the Stoner criterion in a Landau-Fermi liquid with weak non-zero gauge field. Due to a process analogous to Kohn's theory of a metal-insulator transition, we find the stability of a Fermi liquid phase in the absence of non-quasiparticle contributions to the response is strongly dependent on Landau parameters of mixed partial waves. Our work paves the way for the description of novel spintronic hardware in the language of Landau-Fermi liquid transport.
Carrier Tuning of Stoner Ferromagnetism in ThCr$_{\mathbf{2}}$Si$_{\mathbf{2}}$-Structure Cobalt Arsenides
CaCo $_{2-y}$作为$_2$是一种不寻常的巡回磁铁与签名的极端磁挫折。在这种流动的阻挫磁体中建立磁秩序的条件,无论是通过减少阻挫还是增加电子相关,都是一个悬而未决的问题。在这里,我们使用非弹性中子散射和磁化率测量和密度泛函理论计算的结果表明,空穴掺杂在Ca(Co $_{1-x}$ Fe $_{x}$)$_{2-y}$作为$_{2}$抑制磁序淬火的磁矩,同时保持相同的水平的磁挫折。这种抑制是由于将费米能从源自平坦导带的电子态密度的峰值中调谐开。这导致磁矩被$x\approx0.25$完全消除,从而提供了一个Stoner型转变的明显例子。
Colossal band renormalization and stoner ferromagnetism induced by electron-antiferromagnetic-magnon coupling
电子与反铁磁振子之间的相互作用对一大类相关材料都很重要。例如,它们是高温超导体(如铜酸盐和铁磷属元素化物)中最合理的配对胶。然而,与电子-声子相互作用(EPI)不同,关于电子-AFMM相互作用(EAI)如何影响能带结构的明确观察仍然缺乏。因此,关于EAI的关键信息,例如其强度和掺杂依赖性,仍然难以捉摸。在这里,我们直接观察到,EAI诱导的带色散在Ba $_{1-x}$ K $_x$ Mn $_2$ As $_2$的扭结结构,并随后揭示了EAI的几个关键特征。我们发现,EAI的耦合常数可以高达6,它显示出巨大的掺杂依赖性和温度依赖性,所有这些都与EPI的行为形成鲜明对比,超出了我们目前对EAI的理解。EAI对电子能带的这种巨大重整化使系统达到Stoner判据,给出了Ba $_{1-x}$ K $_x$ Mn $_2$ As $_2$中有趣的铁磁态。我们的研究结果扩展了EAI的现有知识,这可能有助于进一步了解许多相关材料,其中EAI发挥关键作用,如高温超导体。
Stoner transitions beyond mean-field in two-dimensional electronic systems: a diagrammatic Monte Carlo study
School of Physics and Astronomy and William I. Fine Theoretical Physics Institute, University of Minnesota(明尼苏达大学物理与天文学学院及威廉·I·芬恩理论物理研究所);Department of Physics, University of Massachusetts, Amherst(马萨诸塞大学阿默斯特分校物理系)
Nesting-driven ferromagnetism of itinerant electrons
Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences(俄罗斯科学院理论与应用电动力学研究所);National Research University Higher School of Economics(国立高等经济大学);National University of Science and Technology MISIS(莫斯科国立科学与技术大学MISIS)
Inducing ferromagnetism by structural engineering in a strongly spin-orbit coupled oxide
Universität Würzburg(维尔茨堡大学);International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences(波兰科学院物理研究所磁顶国际研究中心);CNR-SPIN, UOS Salerno(萨莱诺国家研究委员会自旋单元);Leibniz Institute for Solid State and Materials Research Dresden(德累斯顿莱布尼兹固体与材料研究所);TU Dresden(德累斯顿工业大学);Synchrotron SOLEIL(索雷尔同步辐射中心)