Megahertz dynamics in skyrmion systems probed with muon-spin relaxation

具有Néel型斯格明子晶格的极性磁体GaV$_4$Se$_8$的磁结构探测：基于$^{51}$V NMR研究

Magnetic structure of polar magnet GaV$_4$Se$_8$ with Néel-type skyrmion lattice probed by $^{51}$V NMR

本研究通过$^{51}$V NMR测量了极性磁体GaV$_4$Se$_8$，揭示了不同结构畴中的摆动态、锥形态及强制铁磁态特征，并发现斯格明子晶格态信号因低能激发导致的衰减率增加而消失。

Spin phases of the helimagnetic insulator Cu$_2$OSeO$_3$ probed by magnon heat conduction

We report studies of thermal conductivity as functions of magnetic field and temperature in the helimagnetic insulator Cu$_2$OSeO$_3$ that reveal novel features of the spin-phase transitions as probed by magnon heat conduction. The tilted conical spiral and low-temperature skyrmion phases, recently identified in small-angle neutron scattering studies, are clearly identified by sharp signatures in the magnon thermal conductivity. Magnon scattering associated with the presence of domain boundaries in the tilted conical phase and regions of skyrmion and conical-phase coexistence are identified.

Magnetic phases of skyrmion-hosting GaV$_4$S$_{8-y}$Se$_{y}$ ($y = 0, 2, 4, 8$) probed with muon spectroscopy

We present the results of a muon-spin spectroscopy investigation of GaV$_4$S$_{8-y}$Se$_{y}$ with $y=0, 2, 4$ and 8. Zero-field measurements suggest that GaV$_{4}$Se$_{8}$ and GaV$_{4}$S$_{8}$ have distinct magnetic ground states, with the latter material showing an anomalous temperature-dependence of the local magnetic field. It is not possible to evolve the magnetic state continuously between these two systems, with the intermediate $y=2$ and $4$ materials showing glassy magnetic behaviour at low temperature. The skyrmion lattice (SkL) phase is evident in the $y=0$ and 8 materials through an…

Skyrmion lattice with a giant topological Hall effect in a frustrated triangular-lattice magnet

Geometrically frustrated magnets provide abundant opportunities for discovering complex spin textures, which sometimes yield unconventional electromagnetic responses in correlated electron systems. It is theoretically predicted that magnetic frustration may also promote a topologically nontrivial spin state, i.e., magnetic skyrmions, which are nanometric spin vortices. Empirically, however, skyrmions are essentially concomitant with noncentrosymmetric lattice structures or interfacial-symmetry-breaking heterostructures. Here, we report the emergence of a Bloch-type skyrmion state in the frustr…

Hybrid Bloch-Néel spiral states in Mn$_{1.4}$PtSn probed by resonant soft x-ray scattering

Multiple intriguing phenomena have recently been discovered in tetragonal Heusler compounds, where $D_{2d}$ symmetry sets a unique interplay between Dzyaloshinskii-Moriya (DM) and magnetic dipolar interactions. In the prototype $D_{2d}$ compound Mn$_{1.4}$PtSn, this has allowed the stabilization of exotic spin textures such as first-reported anti-skyrmions or elliptic Bloch-type skyrmions. While less attention has so far been given to the low-field spiral state, this remains extremely interesting as a simplest phase scenario on which to investigate the complex hierarchy of magnetic interaction…

非常规电荷密度波材料 $1\ extit{T'}-\ ext{TaTe}_2$ 中以兆赫兹速率循环的飞秒三聚体淬灭

Femtosecond trimer quench cycled at megahertz rates in the unconventional charge-density wave material $1\textit{T'}-\text{TaTe}_2$

利用超快纳米束电子衍射研究 $1T'-TaTe_2$，揭示其低温三聚体晶格在 2 MHz 光激发下于 500 fs 内发生方向性协同淬灭，而室温周期晶格畸变异常稳健。