arXiv subjects

Yishui Zhou

Publications and source records attributed to Yishui Zhou.

4 recordsLinked to original sources

arXiv2026

Magnetic structure in the two-dimensional van der Waals ferromagnet Fe$_3$GaTe$_2$

High-quality single crystals of the two-dimensional van der Waals ferromagnet Fe$_3$GaTe$_2$ (FGaT) were successfully grown using the chemical vapour transport method, which effectively reduced surface impurities compared with conventional self-flux growth. Structural and magnetic characterizations were performed using single-crystal X-ray and neutron diffraction. The results confirm that FGaT crystallizes in the hexagonal $P6_3/mmc$ structure, with Fe occupying two inequivalent sites (Fe$^{i}$ and Fe$^{ii}$), where the magnetic moment of Fe$^{i}$ [1.9(2) $\mu_B$] is larger than that of Fe$^{ii}$ [1.4(6) $\mu_B$]. The magnetic easy axis is oriented along the $c$ axis and the Curie temperature ($T_C$) is approximately 355-360 K. Compared with Fe$_3$GeTe$_2$ (FGT), FGaT exhibits a slightly expanded $a$ axis and a contracted $c$ axis, resulting in a reduction in the Fe$^{i}$-Fe$^{ii}$ interatomic distance along the $c$ axis. This pronounced contraction could strengthen the Fe$-$Fe exchange interaction, which is believed to be the key factor responsible for the significantly higher $T_C$ in FGaT relative to FGT.

cond-mat.str-el↗

arXiv2026

Coexistence of long-range magnetic order and dynamical magnetism in the V-based Kagome metals: A combined thermodynamic and $\mu$SR study

V-based Kagome metals exhibit a unique lattice geometry that can give rise to exotic electronic and magnetic phenomena, making them an ideal platform to study the interplay of topology and magnetism. We present a combined thermodynamic and muon spin relaxation ($\mu$SR) investigation of single-crystal RV$_{6}$Sn$_{6}$ (R = Tb, Dy, Ho, Er) compounds, focusing on their low-temperature magnetic behavior. Heat capacity and $\mu$SR measurements reveal distinct magnetic phase transitions below 4 K, confirming the emergence of long-range magnetic order in all compounds studied. The $\mu$SR results further indicate persistent spin fluctuations within the magnetically ordered state down to 50 mK, reflected in reduced ordered moments obtained from hyperfine analysis of the heat capacity measurements. These findings uncover the coexistence of static and dynamic magnetism in V-based Kagome metals and emphasizing the key role of 4$f$-electron anisotropy in shaping their magnetic ground states. Compared with the Mn-based RMn$_{6}$Sn$_{6}$ analogs, our results highlight the unique magnetism arising from the decoupled rare-earth sublattice and its interplay with the nonmagnetic V Kagome network.

cond-mat.str-el↗

arXiv2025

Single domain spectroscopic signatures of a magnetic Kagome metal

Spin- and orbital-resolved access to the electronic bands is necessary to establish key properties of quantum materials such as the quantum-geometric tensor. Despite recent revival on magnetic Kagome compounds, no spectroscopic access to their magnetic properties has been available so far due to small domain sizes and lack of appropriate techniques. Furthermore, their real space magnetic texture is often complex and temperature-dependent. We investigate the magnetic Kagome metal DyMn$_6$Sn$_6$ using high-resolution micro-focused circular-dichroic angle-resolved photoemission ($\mu$-CD-ARPES) to probe its magnetic and electronic properties. By tuning the kinetic energy to various features of the Dy $4f$ multiplet, we resolve magnetic domains in samples cryo-cooled down to 20 K. Smaller, but clear signatures are detected in the Mn $3p$ levels. The behavior of both Dy $4f$ and Mn $3p$ features are in remarkable agreement with our modeling based on the Hartree-Fock method, revealing ferrimagnetic alignment of Dy and Mn local moments, and further strengthening our interpretation. Adjusting the energy to the Mn $3d$-dominated valence bands reveals signatures which we relate to the orbital magnetization through a comparison to {\it ab initio} electronic structure calculations. Our study establishes the spectroscopic access to a single magnetic domain in a Kagome metal, paving the way for further research into imaging magnetic phases of novel magnetic materials using $\mu$-CD-ARPES.

cond-mat.mtrl-sci↗

arXiv2024

Ground-state magnetic structures of topological kagome metals RV$_6$Sn$_6$ (R = Tb, Dy, Ho, Er)

Magnetic kagome metals have attracted tremendous research interests recently, because they represent an ideal playground for exploring the fascinating interplay between their intrinsically inherited topologically non-trivial electron band structures, magnetism and electronic correlation effects, and the resultant novel electronic/magnetic states and emergent excitations. In this work, we report a comprehensive single-crystal neutron diffraction investigation of the ground-state magnetic structures of the recently discovered V-based topological kagome metals RV$_6$Sn$_6$ (R = Tb, Dy, Ho, Er). Furthermore, the sample synthesis details and our systematic studies of crystal structure, low-temperature magnetic and thermodynamic properties of these compounds via various in-house characterization techniques are also reported. It can be revealed that RV$_6$Sn$_6$ (R = Tb, Dy, Ho) have a collinear ferromagnetic order in the ground state, with the ordered magnetic moment aligned along the c axis for R = Tb, Ho, while approximately 20${^\circ}$ tilted off from the c axis for R = Dy. In contrast, ErV$_6$Sn$_6$ shows an A-type antiferromagnetic structure with a magnetic propagation vector k = (0, 0, 0.5), and with the ordered magnetic moment aligned in the ab plane. A comparison of the low-temperature magnetic structures for both the extensively investigated topological kagome metal series of RV$_6$Sn$_6$ and RMn$_6$Sn$_6$ is given in details. This allows to gain new insights into the complex magnetic interactions, diverse single-ion magnetic anisotropies and spin dynamics in these compounds. The reported ground-state magnetic structures in RV$_6$Sn$_6$ (R = Tb, Dy, Ho, Er) can pave the way for further explorations of the possible interplay between magnetism and topologically non-trivial electron band structures in the magnetically ordered phase regime.

cond-mat.str-el↗