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Abstract 1D charge transport offers great insight into strongly correlated physics, such as Luttinger liquids, electronic instabilities, and superconductivity. Although 1D charge transport is observed in nanomaterials and quantum wires, examples in bulk crystalline solids remain elusive. In this work, it is demonstrated that spin‐orbit coupling (SOC) can act as a mechanism to induce quasi‐1D charge transport in the Ln₃MPn₅(Ln = lanthanide; M = transition metal; Pn = Pnictide) family. From three example compounds, La₃ZrSb₅, La₃ZrBi₅, and Sm₃ZrBi₅, density functional theory calculations with SOC included show a quasi‐1D Fermi surface in the bismuthide compounds, but an anisotropic 3D Fermi surface in the antimonide structure. By performing anisotropic charge transport measurements on La₃ZrSb₅, La₃ZrBi₅, and Sm₃ZrBi₅, it is demonstrated that SOC starkly affects their anisotropic resistivity ratios (ARR) at low temperatures, with an ARR of ≈4 in the antimonide compared to ≈9.5 and ≈22 (≈32 after magnetic ordering) in La₃ZrBi₅and Sm₃ZrBi₅, respectively. This report demonstrates the utility of spin‐orbit coupling to induce quasi‐low‐dimensional Fermi surfaces in anisotropic crystal structures, and provides a template for examining other systems. 

Abstract While several magnetic topological semimetals have been discovered in recent years, their band structures are far from ideal, often obscured by trivial bands at the Fermi energy. Square‐net materials with clean, linearly dispersing bands show potential to circumvent this issue. CeSbTe, a square‐net material, features multiple magnetic‐field‐controllable topological phases. Here, it is shown that in this material, even higher degrees of tunability can be achieved by changing the electron count at the square‐net motif. Increased electron filling results in structural distortion and formation of charge density waves (CDWs). The modulation wave‐vector evolves continuously leading to a region of multiple discrete CDWs and a corresponding complex “Devil's staircase” magnetic ground state. A series of fractionally quantized magnetization plateaus is observed, which implies direct coupling between CDW and a collective spin‐excitation. It is further shown that the CDW creates a robust idealized nonsymmorphic Dirac semimetal, thus providing access to topological systems with rich magnetism. 

Abstract Van der Waals (vdW) materials are an indispensable part of functional device technology due to their versatile physical properties and ease of exfoliating to the low‐dimensional limit. Among all the compounds investigated so far, the search for magnetic vdW materials has intensified in recent years, fueled by the realization of magnetism in 2D. However, metallic magnetic vdW systems are still uncommon. In addition, they rarely host high‐mobility charge carriers, which is an essential requirement for high‐speed electronic applications. Another shortcoming of 2D magnets is that they are highly air sensitive. Using chemical reasoning, TaCo₂Te₂is introduced as an air‐stable, high‐mobility, magnetic vdW material. It has a layered structure, which consists of Peierls distorted Co chains and a large vdW gap between the layers. It is found that the bulk crystals can be easily exfoliated and the obtained thin flakes are robust to ambient conditions after 4 months of monitoring using an optical microscope. Signatures of canted antiferromagntic behavior are also observed at low‐temperature. TaCo₂Te₂shows a metallic character and a large, nonsaturating, anisotropic magnetoresistance. Furthermore, the Hall data and quantum oscillation measurements reveal the presence of both electron‐ and hole‐type carriers and their high mobility.