Static and dynamical magnetic and electronic properties of the kagome metal Sc$_3$Mn$_3$Al$_7$Si$_5$ have been investigated by $^{27}$Al nuclear magnetic resonance (NMR) measurements. The temperature dependence of Knight shift ($K$) shows a similar temperature dependence of the DC magnetic susceptibility $χ$ except for the low-temperature region below $\sim$ 50 K where $K$ is almost constant while $χ$ keeps increasing, which suggests that the increase in $χ$ at low temperatures is not intrinsic. $^{27}$Al spin-lattice relaxation rate divided by temperature ($1/T_1T$) is found to be constant, confirming the metallic state of Sc$_3$Mn$_3$Al$_7$Si$_5$ from a microscopic point of view. Based on a Korringa ratio analysis using the $T_1$ and $K$ data, ferromagnetic spin fluctuations are found to dominate in Sc$_3$Mn$_3$Al$_7$Si$_5$. These fluctuations are suggested to be very slow with frequencies on the order of kilohertz or lower.
Ground State and Intrinsic Susceptibility of the Kagome Antiferromagnet Vesignieite as seen by 51V NMR
用51 V核磁共振测量了近kagome量子磁体vesignieite Cu 3BaV 2 O 8（OH）2的内禀磁化率和局部磁化强度。核磁共振谱线位移给出了一个精确的测量的内在磁化率的kagome网站，这非常类似的量子自旋液体herbertsmithite [A. Olariu等人，Phys. Rev. Lett. 100，087202（2008）]。因此，令人惊讶的是，在Tc ~ 9 K时，观察到向异质基态的转变。一个逐渐wipeout的一半的NMR强度表明一个缓慢波动的自旋液体成分和线宽的详细分析揭示了静态磁性的发病在其余一半的网站。我们认为这种跃迁和不寻常的基态起源于Dzyaloshinskiii-Moriya相互作用诱导的一个量子临界点附近。
Kagome lattice Heisenberg antiferromagnets are known to be highly sensitive to perturbations caused by structural disorder. NMR is a local probe ideally suited for investigating such disorder-induced effects, but in practice large distributions in the conventional one-dimensional NMR data make it difficult to distinguish the intrinsic behavior expected for pristine kagome quantum spin liquids from disorder induced effects. Here we report the development of a two-dimensional NMR data acquisition scheme applied to Zn-barlowite (Zn$_{0.95}$Cu$_{0.05}$)Cu$_{3}$(OD)$_{6}$FBr kagome lattice, and suc…
Canted Antiferromagnetic Order in the Kagome Material Sr-Vesignieite
本文报道了一种$S = 1/2$类海森堡反铁磁体Sr-vesignieite，SrCu $_3$ V $_2$ O $_8$（OH）$_2$粉末样品的$^{51}$ V NMR，$μ$ SR和零场$^{63,65}$ Cu NMR测量结果。我们的结果表明，基态是一个$\mathbf{q} = 0$磁结构，自旋倾斜或在戈薇平面外，产生弱铁磁性。我们确定的大小有序的时刻和倾斜的角度为不同的可能的$\mathbf{q} = 0$结构和轨道的情况下，从而提供洞察的Dzyaloshinskiii-Moriya（DM）在这种材料中的相互作用的作用。
We report $^{121/123}$Sb nuclear quadrupole resonance (NQR) and $^{51}$V nuclear magnetic resonance (NMR) measurements on kagome metal CsV$_3$Sb$_5$ with $T_{\rm c}=2.5$ K. Both $^{51}$V NMR spectra and $^{121/123}$Sb NQR spectra split after a charge density wave (CDW) transition, which demonstrates a commensurate CDW state. The coexistence of the high temperature phase and the CDW phase between $91$ K and $94$ K manifests that it is a first order phase transition. At low temperature, electric-field-gradient fluctuations diminish and magnetic fluctuations become dominant. Superconductivity eme…
The neutron diffraction and nuclear magnetic resonance (NMR) measurements have been used to microscopically analyze the magnetic structure in the $S = 1/2$ kagome antiferromagnet CdCu$_{3}$(OH)$_{6}$(NO$_{3}$)$_{2}\cdot $H$_{2}$O. Below the magnetic ordering temperature $T_N\simeq 4$ K, magnetic Bragg reflections at (110) and (100) were found in the neutron diffraction pattern, which suggests a $q=0$ magnetic structure. Furthermore, the vector spin chirality for the $q=0$ structure was successfully identified from the internal field direction obtained by the $^{14}$N-NMR measurement. Our findi…
Materials with zero energy band gap display intriguing properties including high sensitivity of the electronic band structure to external stimulus such as pressure or magnetic field. An interesting candidate for zero energy band gap are Weyl nodes at the Fermi level EF. A prerequisite for the existence of Weyl nodes is to either have inversion or time reversal symmetry broken. Weyl nodes in systems with broken time reversal symmetry are ideal to realize the tunability of the electronic band structure by magnetic field. Theoretically, it has been shown that in ferromagnetic Weyl materials, the …
Competing magnetic correlations across the ferromagnetic quantum critical point in the Kondo system CeTi$_{1-x}$V$_x$Ge$_3$: $^{51}$V NMR as a local probe
对CeTi $_{1-x}$ V $_x$ Ge $_3$进行了$^{51}$ V核磁共振（NMR）和磁化强度的研究，以探索从铁磁（$x = 0.113$）到反铁磁近藤晶格态（$x = 1$）的演化，重点关注在$x_c \approx 0.4$处可能出现的铁磁量子临界点（FMQCP）.从核自旋-晶格弛豫速率$1/T_1T$和Knight位移\textit{K}的温度依赖关系中发现，在$x=0.113$和$x=1$的临界浓度（$x = 0.35, 0.405$）附近，量子临界自旋涨落伴随着弱的反铁磁自旋涨落和铁磁自旋涨落.因此，CeTi $_{1-x}$ V $_x$ Ge $_3$中的FMQCP本质上不是纯铁磁的。
Two Dimensional Kagome Correlations and Field Induced Order in the Ferromagnetic XY Pyrochlore Yb2Ti2O7
中子散射测量表明，铁磁XY烧绿石Yb 2 Ti 2 O 7在低温下表现出很强的准二维（2D）自旋关联，在适当的磁场作用下，这种关联让位于长程序（LRO）.由于< 111 >这些2D自旋相关性沿方向的散射棒意味着立方烧绿石系统的磁分解成解耦的可果美平面。沿[1-10]方向施加约0.5 T的磁场，诱导向3D LRO状态的转变，其特征在于长寿命的色散自旋波。我们的测量绘制出一个复杂的低温场相图，这种异国情调的烧绿石磁铁。
Ga NMR study of the local susceptibility in SrCr8Ga4O19: pseudogap and paramagnetic defects
本文首次用Ga（4 f）NMR研究了Kagome基阻挫反铁磁体原型SrCr $_{8}$ Ga $_{4}$ O $_{19}$中Cr的磁化率.我们的主要发现是受抑晶格的磁化率在50 K附近经历一个最大值。我们的数据也支持存在顺磁性自旋“团簇”，这是在低温下宏观磁化率中观察到的居里行为的原因。这些结果为几何阻挫磁体的物理学争论不休提供了新的特征。
Recently, competing electronic instabilities, including superconductivity and density-wave-like order, have been discovered in vanadium-based kagome metals AV3Sb5 (A = K, Rb, Cs) with a nontrivial band topology. This finding stimulates wide interests to study the interplay of these competing electronic orders and possible exotic excitations in the superconducting state. Here, in order to further clarify the nature of density-wave-like transition in these kagome superconductors, we performed 51V and 133Cs nuclear magnetic resonance (NMR) measurements on the CsV3Sb5 single crystal. A first-order…
Massive Dirac fermions in a ferromagnetic kagome metal
kagome晶格是一个由角共享三角形组成的二维网络，被称为奇异量子磁态的平台。理论工作已经预测，kagome晶格也可能拥有狄拉克电子态，这可能导致拓扑和陈氏绝缘相，但这些都逃避了实验检测到日期。在这里，我们研究的d-电子kagome金属Fe $_3$ Sn $_2$设计支持大规模狄拉克费米子在铁磁秩序的存在下。我们观察到一个温度无关的固有的异常霍尔电导率持续高于室温暗示突出的Berry曲率从时间反演打破电子带的戈薇平面。使用角分辨光电发射，我们发现一对准二维狄拉克锥附近的费米能级与30 meV的质量间隙，占贝里曲率诱导的霍尔电导率。我们发现，这种行为是一个结果的基本对称性的双层kagome晶格在铁磁态原子自旋轨道耦合。这份报告提供了铁磁戈薇金属的第一个证据和一个例子，新兴的拓扑电子性质的相关电子系统。这提供了洞察最近发现的奇异的电子行为在kagome晶格反铁磁体，并可能提供一个垫脚石走向分数拓扑量子态的晶格模型实现。
We report on the low-energy dynamics in the kagome antiferromagnet CaCu$_3$(OD)$_6$Cl$_2\cdot0.6$D$_2$O (Ca-kapellasite) as studied by use of $^2$D-NMR measurements. Previous $^{35}$Cl-NMR measurements revealed that the nuclear spin-lattice relaxation rate ($1/T_1$) shows two peaks at temperatures, $T^{\ast} = 7.2$ K and $T_s \simeq 25$ K. While the low-temperature peak at $T^{\ast}$ is ascribed to the critical fluctuations near the long-range magnetic ordering, the origin of the high-temperature peak has not been fully understood. From the $1/T_1$ measurements on the D sites at the OD groups …
Gapped 1/9 Magnetization Plateau in the Anisotropic Kagome Antiferromagnet Y-kapellasite
Université Paris-Saclay（巴黎萨克雷大学）；CNRS（法国国家科学研究中心）；Laboratoire de Physique des Solides（固体物理实验室）；Clarendon Laboratory, Department of Physics, University of Oxford（牛津大学克拉伦登实验室物理系）；Department of Physics, University of Warwick（华威大学物理系）；Physikalisches Institut, Goethe-Universität Frankfurt（法兰克福歌德大学物理研究所）；Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS (UPR3228), EMFL, Univ. Grenoble Alpes, Univ. Toulouse, INSA-T（强磁场国家实验室，LNCMI-CNRS (UPR3228)，欧洲强磁场联合实验室，格勒诺布尔阿尔卑斯大学，图卢兹大学，INSA-T）；Max-Planck-Institute for So（马克斯·普朗克研究所）
$^{139}$La nuclear magnetic resonance (NMR) measurements under pressure ($p = 0-2.64$ GPa) have been carried out to investigate the static and dynamic magnetic properties of the itinerant ferromagnet LaCrGe$_3$. $^{139}$La-NMR spectra for all measured pressures in the ferromagnetically ordered state show a large shift due to the internal field induction $|$$B_{\rm int}$$|$ $\sim$ 4 T at the La site produced by Cr ordered moments. The change in $B_{\rm int}$ by less than 5\% with $p$ up to 2.64~GPa indicates that the Cr 3$d$ moments are robust under pressure. The temperature dependence of NMR s…
