The interplay between dimensionality and superconductivity is a central theme in understanding the behavior of low-dimensional superconductors. In this work, we investigate the dimensional crossover from quasi-two-dim...The interplay between dimensionality and superconductivity is a central theme in understanding the behavior of low-dimensional superconductors. In this work, we investigate the dimensional crossover from quasi-two-dimensional(quasi-2D) to three-dimensional(3D) superconductivity in(Li,Fe)OHFeSe_(1-x)S_(x) single crystals driven by sulfur doping.Through detailed structural, electrical, and magnetic characterization, we identify a critical doping level(x = 0.53) where the system transitions from quasi-2D to 3D superconducting behavior. Reduced superconducting fluctuations and nonFermi liquid behavior near this critical point suggest the presence of competition between intralayer and interlayer pairing mechanisms. Fluctuation conductivity analysis reveals that the coherence length along the c-axis, ζ_(c)(0), and the interlayer coupling strength, Γ, increase significantly at x = 0.53, marking the onset of 3D superconductivity. These findings provide new insights into the role of dimensionality and interlayer coupling in modulating superconducting properties, positioning(Li,Fe)OHFeSe_(1-x)S_(x) as a unique platform for exploring crossover physics in iron-based superconductors.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 52272268, 52250308, and 52102338)Beijing National Laboratory for Condensed Matter Physics (Grant No. 2024BNLCMPKF016)Fundamental Research Funding of Universities directly under the Chinese Central Government (Grant No. 2-9-2022-038)。
文摘The interplay between dimensionality and superconductivity is a central theme in understanding the behavior of low-dimensional superconductors. In this work, we investigate the dimensional crossover from quasi-two-dimensional(quasi-2D) to three-dimensional(3D) superconductivity in(Li,Fe)OHFeSe_(1-x)S_(x) single crystals driven by sulfur doping.Through detailed structural, electrical, and magnetic characterization, we identify a critical doping level(x = 0.53) where the system transitions from quasi-2D to 3D superconducting behavior. Reduced superconducting fluctuations and nonFermi liquid behavior near this critical point suggest the presence of competition between intralayer and interlayer pairing mechanisms. Fluctuation conductivity analysis reveals that the coherence length along the c-axis, ζ_(c)(0), and the interlayer coupling strength, Γ, increase significantly at x = 0.53, marking the onset of 3D superconductivity. These findings provide new insights into the role of dimensionality and interlayer coupling in modulating superconducting properties, positioning(Li,Fe)OHFeSe_(1-x)S_(x) as a unique platform for exploring crossover physics in iron-based superconductors.
