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arXiv · 2507.14540

The Anisotropy of Thermal Activation Energy of 2H-NbS$_2$

Yang Wang·Pengjian Tan·Mingxi Chi·Boxi Wei·Anchun Ji·Jian Wang·He Wang
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Abstract

We investigate the anisotropic flux dynamics in 2H-NbS$_2$ single crystals through temperature-dependent resistance measurements under in-plane ($H \parallel ab$ plane) and out-of-plane ($H \perp ab$ plane) magnetic fields. Analysis of thermally activated flux flow (TAFF) resistance in the superconducting mixed state reveals stark contrasts in thermal activation energy ($U_0$) scaling and field dependence. For $H \perp ab$, $U_0(0.1 \mathrm{T}) = (1228.76 \pm 53.64)$ K follows the Arrhenius relation with a power-law field decay ($U_0\propto H^{-\alpha}$). In contrast, under $H \parallel ab$, $U_0(0.5 \mathrm{T}) = (7205.58 \pm 619.65)$ K aligns with the modified TAFF theory, where the scaling exponent $q = 2$ potentially reflects two-dimensional vortex behavior in the TAFF region, and the field dependence of $U_0$ follows parabolic relation $H^{\gamma}\left[1 - \frac{H}{H^{*}}\right]^2$. These results establish 2H-NbS$_2$ as a model system for probing the anisotropy of flux dynamics in layered superconductors.

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Yang Wang, Pengjian Tan, Mingxi Chi, Boxi Wei, Anchun Ji, Jian Wang, He Wang. 2025-07-19. The Anisotropy of Thermal Activation Energy of 2H-NbS$_2$. https://doi.org/10.1063/10.0037011

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