Self-stacked 1$\mathrm{T}$-1$\mathrm{H}$ layers in 6$\mathrm{R}$-NbSeTe and the emergence of charge and magnetic correlations due to ligand disorder

S. K. Mahatha; J. Phillips; J. Corral-Sertal; D. Subires; A. Korshsunov; A. Kar; J. Buck; F. Diekmann; Y. P. Ivanov; A. Chuvilin; D. Mondal; I. Vobornik; A. Bosak; K. Rossnagel; V. Pardo; Adolfo O. Fumega; S. Blanco-Canosa

arXiv · 2402.07609

Self-stacked 1$\mathrm{T}$-1$\mathrm{H}$ layers in 6$\mathrm{R}$-NbSeTe and the emergence of charge and magnetic correlations due to ligand disorder

S. K. Mahatha·J. Phillips·J. Corral-Sertal·D. Subires·A. Korshsunov·A. Kar·J. Buck·F. Diekmann·Y. P. Ivanov·A. Chuvilin·D. Mondal·I. Vobornik·A. Bosak·K. Rossnagel·V. Pardo·Adolfo O. Fumega·S. Blanco-Canosa

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Abstract

The emergence of correlated phenomena arising from the combination of 1$\mathrm{T}$ and 1$\mathrm{H}$ van der Waals layers is the focus of intense research. Here, we synthesize a novel self-stacked 6$\mathrm{R}$ phase in NbSeTe, showing a perfect alternating 1T and 1H layers that grow coherently along the c-direction, as revealed by scanning transmission electron microscopy. Angle resolved photoemission spectroscopy shows a mixed contribution of the trigonal and octahedral Nb bands to the Fermi level. Diffuse scattering reveals temperature-independent short-range charge fluctuations with propagation vector $\mathrm{q_{CO}}$=(0.25,0), derived from the condensation of a longitudinal mode in the 1T layer. We observe that ligand disorder quenches the formation of a charge density wave. Magnetization measurements suggest the presence of an inhomogeneous, short-range magnetic order, further supported by the absence of a clear phase transition in the specific heat. These experimental analyses in combination with \textit{ab initio} calculations indicate that the ground state of 6$\mathrm{R}$-NbSeTe is described by a statistical distribution of short-range charge-modulated and spin-correlated regions driven by ligand disorder. Our results devise a route to synthesize 1$\mathrm{T}$-1$\mathrm{H}$ self-stacked bulk heterostructures to study emergent phases of matter.

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S. K. Mahatha, J. Phillips, J. Corral-Sertal, D. Subires, A. Korshsunov, A. Kar, J. Buck, F. Diekmann, Y. P. Ivanov, A. Chuvilin, D. Mondal, I. Vobornik, A. Bosak, K. Rossnagel, V. Pardo, Adolfo O. Fumega, S. Blanco-Canosa. 2024-02-12. Self-stacked 1$\mathrm{T}$-1$\mathrm{H}$ layers in 6$\mathrm{R}$-NbSeTe and the emergence of charge and magnetic correlations due to ligand disorder. https://arxiv.org/abs/2402.07609

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