Highlights
Triangular Kondo lattice in YbV6Sn6 and its quantum critical behavior in a magnetic field
We report on the magnetization, specific heat, and electrical resistivity for a newly discovered heavy-fermion  (HF) compound, YbV 6 Sn 6 , which is crystallized in a hexagonal HfFe 6 Ge 6 -type structure, highlighted by the  stacking of the triangular ytterbium sublattice and kagome vanadium sublattice. Above 2 K,  YbV 6 Sn 6 shows  typical HF properties due to the Kondo effect on the Kramers doublet of Yb 3+ ions in the crystalline electric  field. A remarkable magnetic       ordering occurs at T N = 0 . 40 K in zero field, while a weak external field suppresses  the ordering and induces non-Fermi-liquid behavior. In strong magnetic        field, the compound shows a heavy  Fermi-liquid state. YbV 6 Sn 6 is represented as one of the few examples of Yb-based HF compounds hosting a  triangular Kondo lattice on which a magnetic field induces quantum criticality near zero temperature.  Phys. Rev. B  107, 205151 (2023) PhysRevB.107.205151.pdf


1/3 and other magnetization plateaus in the quasi-one-dimensional Ising magnet TbTi3Bi4 with zigzag spin chain

We report the magnetic properties of newly synthesized single crystals of TbTi₃Bi₄, featuring alternating terbium-based zigzag chains and titanium-based kagome lattices. The compound exhibits extreme easy-axis magnetic anisotropy due to crystalline-electric-field effects that align Tb³⁺ moments along the chain direction. Combined strong single-ion anisotropy and competing magnetic interactions lead to quasi-one-dimensional Ising behavior with antiferromagnetic ordering at Tₙ = 20.4 K. Applied magnetic fields along the chain direction induce multiple metamagnetic transitions between 1/3 and other magnetization plateaus. We construct a field-temperature phase diagram and elucidate the complex magnetic structures arising from frustration. [Phys. Rev. B 110, 064416 (2024)] PhysRevB.110.064416.pdf


Quantum-limit Chern topological magnetism in TbMn6Sn6.

The quantum-level interplay between geometry, topology and correlation is at the forefront of fundamental physics. Kagome magnets are predicted to support intrinsic Chern quantum phases owing to their unusual lattice geometry and breaking of time-reversal symmetry. However, quantum materials hosting ideal spin-orbit-coupled kagome lattices with strong out-of-plane magnetization are lacking. Here, using scanning tunnelling microscopy, we identify a new topological kagome magnet, TbMn6Sn6, that is close to satisfying these criteria.Nature, 583, 533-536 (2020). PDF Download

Bond-breaking induced Lifshitz transition in robust Dirac semimetal VAl3

Topological electrons in semimetals are usually vulnerable to a chemical doping and environment change, which restricts their potential application in future electronic devices. In this paper, we report that the type-II Dirac semimetal VAl3 hosts exceptional, robust topological electrons which can tolerate extreme change of chemical composition. The Dirac electrons remain intact, even after a substantial part of V atoms have been replaced in the V1−xTixAl3 solid solutions.PNAS, July 7, 2020 117 (27) 15517-15523. PDF Download

Non-saturating quantum magnetization in Weyl semimetal TaAs.

Detecting the spectroscopic signatures of relativistic quasiparticles in emergent topological materials is crucial for searching their potential applications. Magnetometry is a powerful tool for fathoming electrons in solids, by which a clear method for discerning relativistic quasi particles has not yet been established. Adopting the probes of magnetic torque and parallel magnetization for the archetype Weyl semimetal TaAs in strong magnetic field, we observed a quasi-linear field dependent effective transverse magnetization and a non-saturating par allel magnetization when the system enters the quantum limit. Distinct from the saturating magnetic responses for non-relativistic quasiparticles, the non-saturating signals of TaAs in strong field is consistent with our newly developed magnetization calculation for a Weyl fermion system in an arbitrary angle. Our results establish a high-field thermodynamic method for detecting the magnetic response of relativistic quasiparticles in topological materials.Nat. Commun. 10, 1028 (2019). PDF Download

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