基于分子的自旋为1/2的三角晶格系统如LiZn $_2$ Mo $_3$ O $_8$引起了研究兴趣。扭曲,缺陷,和intersite无序抑制在这样的分子基磁体,和内在的几何挫折引起非常规和意想不到的基态。Li $_2$ $A$ Mo $_3$ O $_8$($A$ = In或Sc)是这样一种化合物,其中自旋为1/2的Mo $_3$ O $_{13}$簇代替Mo离子形成均匀的三角形晶格。它们的基态根据$A$位点而不同。Li $_2$ InMo $_3$ O $_8$在低于$T_\text{N}=12$ ~K时经历常规的$120^\circ$长程磁序,而同晶Li $_2$ ScMo $_3$ O $_8$在低于0.5~K时没有长程磁序.在这里,我们报告奇异的磁性在Li $_2$ InMo $_3$ O $_8$和Li $_2$ ScMo $_3$ O $_8$调查的μ子自旋旋转($μ$ SR)和非弹性中子散射(INS)光谱使用多晶样品。Li $_2$ InMo $_3$ O $_8$和Li $_2$ ScMo $_3$ O $_8$显示在$μ$ SR和INS测量中观察到的完全不同的行为,代表它们不同的基态。Li $_2$ InMo $_3$ O $_8$表现出自旋波激发,其由基于$120^\circ$自旋结构的最近邻各向异性海森堡模型定量描述。相反,Li $_2$ ScMo $_3$ O $_8$在低于4 K的温度下经历短程磁序,并在低于基温时具有类似量子自旋液体的磁涨落。从晶体结构的各向异性和磁相互作用的角度讨论了不同基态的起源。
英文摘要:
Molecular based spin-1/2 triangular lattice systems such as LiZn$_2$Mo$_3$O$_8$ have attracted research interest. Distortions, defects, and intersite disorder are suppressed in such molecular-based magnets, and intrinsic geometrical frustration gives rise to unconventional and unexpected ground states. Li$_2$$A$Mo$_3$O$_8$ ($A$ = In or Sc) is such a compound where spin-1/2 Mo$_3$O$_{13}$ clusters in place of Mo ions form the uniform triangular lattice. Their ground states are different according to the $A$ site. Li$_2$InMo$_3$O$_8$ undergoes conventional $120^\circ$ long-range magnetic order below $T_\text{N}=12$~K whereas isomorphic Li$_2$ScMo$_3$O$_8$ exhibits no long-range magnetic order down to 0.5~K. Here, we report exotic magnetisms in Li$_2$InMo$_3$O$_8$ and Li$_2$ScMo$_3$O$_8$ investigated by muon spin rotation ($μ$SR) and inelastic neutron scattering (INS) spectroscopies using polycrystalline samples. Li$_2$InMo$_3$O$_8$ and Li$_2$ScMo$_3$O$_8$ show completely different behaviors observed in both $μ$SR and INS measurements, representing their different ground states. Li$_2$InMo$_3$O$_8$ exhibits spin wave excitation which is quantitatively described by the nearest neighbor anisotropic Heisenberg model based on the $120^\circ$ spin structure. In contrast, Li$_2$ScMo$_3$O$_8$ undergoes short-range magnetic order below 4~K with quantum-spin-liquid-like magnetic fluctuations down to the base temperature. Origin of the different ground states is discussed in terms of anisotropies of crystal structures and magnetic interactions.
From magnetism to one-dimensional spin liquid in the anisotropic triangular lattice
我们研究了从解耦的一维链插入到各向同性三角晶格的各向异性三角晶格,并且已被认为与各种准二维材料相关,例如Cs $_2$ CuCl $_4$或$κ$ -(ET)$_2$ Cu $_2$(CN)$_3$,一种显示出有趣磁性的有机材料。我们得到了一个很好的精度通过一个新的表示的共振价键波函数与单重和三重配对。这种方法使我们能够建立,磁秩序是迅速破坏远离纯三角晶格和无公度自旋相关的短范围。非磁性自旋液体自然出现在相图的宽范围内,具有很强的一维特征。还讨论了$κ$ -(ET)$_2$ Cu $_2$(CN)$_3$的三重配对的相关性。
Induced quantum magnetism on a triangular lattice of non-Kramers ions in PrMgAl11O19
Charles University, Faculty of Mathematics and Physics(查理大学数学物理学院);Adam Mickiewicz University, Faculty of Physics and Astronomy(亚当·密茨凯维奇大学物理与天文学学院);Institute of Physics of the Czech Academy of Sciences(捷克科学院物理研究所);Adam Mickiewicz University, NanoBioMedical Centre(亚当·密茨凯维奇大学纳米生物医学中心)
Chiral Magnetism and Quantum Anomalous Hall Effect in a Low-energy Kondo Model on the Triangular Lattice
University of California Santa Barbara(加州大学圣塔芭芭拉分校);Kavli Institute for Theoretical Physics, University of California, Santa Barbara(加州大学圣塔芭芭拉分校卡弗里理论物理研究所);French American Center for Theoretical Science, CNRS, KITP, Santa Barbara, California(法国美国理论科学中心);Canadian Institute for Advanced Research(加拿大高级研究院)
Anisotropic transport and optical spectroscopy study on antiferromagentic triangular lattice EuCd_2As_2: an interplay between magnetism and charge transport properties
Ab initio spin Hamiltonians and magnetism of Ce and Yb triangular-lattice compounds
École polytechnique, Institut Polytechnique de Paris(巴黎综合理工学院,巴黎理工学院);Collège de France, Université PSL(法兰西公学院,巴黎文理研究大学);Max Planck Institute for the Physics of Complex Systems(马克斯·普朗克复杂系统物理研究所)
Frustration-driven unconventional magnetism in the Mn$^{2+}$ ($S=\frac{5}{2}$) based two-dimensional triangular-lattice antiferromagnet Ba$_{3}$MnTa$_{2}$O$_{9}$
Spiral magnetism and chiral superconductivity in Kondo-Hubbard triangular lattice model
在参考文献\cite{faye2018phase}在Kondo-Hubbard正方晶格上发现反铁磁相和Kondo单重相的基础上,我们利用变分集团近似(VCA)研究了具有$120^{o}$自旋取向的二维三角晶格上这些相之间的竞争.除了局域(杂质)和导电(巡游)电子之间的反铁磁交换相互作用$J_{\perp}$外,我们的模型还包括导电电子的局域排斥$U$和杂质之间的海森堡相互作用$J_H$.在半填充时,我们得到了$(J_{\perp}, U J_{\perp})$和$(J_{\perp}, J_{H})$两个平面上的量子相图。我们确定了一个远程,三个亚晶格,螺旋磁秩序占主导地位的小$J_{\perp}$和中等$U$的相图,而近藤单线相变得更稳定,在大$J_{\perp}$。从螺旋磁序到近藤单重态相的转变是一个二级相变。在$(J_{\perp}, J_{H})$平面上,我们观察到$J_H$的作用是减少了近藤单重态相,为螺旋磁有序相提供了更大的空间。还介绍了螺旋磁序参量的一些小磁振荡。在有限掺杂和忽略螺旋磁性的情况下,我们发现了具有对称序参量$d+id$的超导电性,它打破了时间反演对称性。超导序参量在$5\%$空穴掺杂附近有一个圆顶,其振幅随$J_{\perp}$的增大而减小。结果表明,螺旋磁性可以与$d+id$态共存,超导电性受到抑制,表明这两个相是竞争的。
Exotic magnetism and persistent spin dynamics in a frustrated Jeff = 1/2 triangular lattice antiferromagnet
Indian Institute of Technology Madras(印度马德拉斯理工学院);Jožef Stefan Institute(约瑟夫·斯特凡研究所);Faculty of Mathematics and Physics, University of Ljubljana(卢布尔雅那大学数学物理学院);ISIS facility, Rutherford Appleton Laboratory(鲁瑟福阿普尔顿实验室ISIS设施)
Field-Induced Up-Up-Down State and Frustrated Magnetism in a Non-Kramers Triangular Antiferromagnet
Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology(南方科技大学量子科学和工程研究院);International Quantum Academy(国际量子学院);Tsung-Dao Lee Institute, Shanghai Jiao Tong University(上海交通大学李政道研究所);School of Physics and Astronomy, Shanghai Jiao Tong University(上海交通大学物理与天文学院);School of Physics and Electronics, Henan University(河南大学物理与电子学院)
Anisotropic magnetism and spin fluctuations in the triangular-lattice spin-liquid candidate NaYbSe$_2$: a single-crystal $^{23}$Na and $^{77}$Se NMR study
Chemical tuning between triangular and honeycomb structures in a 5$d$ spin-orbit Mott insulator
我们报道了自旋轨道莫特绝缘体家族K $_x$ Ir $_y$ O $_2$的结构研究,具有由钾离子键合的边共享IrO $_6$八面体的三角层。钾含量作为化学调节参数来控制Ir-O层中的电荷量。与Ir被Co或Rh($y=1$)取代的同构家族不同,其在钾组成$x$的范围内是金属性的,我们反而发现通过铱空位实现电荷中性的绝缘行为,其在蜂窝状超电池中在临界组成$x_c$之上有序。通过进行密度泛函理论计算,我们将所观察到的行为归因于一个微妙的相互作用的晶体场环境,本地电子相关性和强大的自旋轨道相互作用在Ir $^{4+}$网站,使这个结构家庭的候选人显示Kitaev磁性在实验未探索的制度,三角形和蜂窝状结构之间的插值。