轻掺杂单层高Tc铜酸盐La₂CuO₄+δ中的磁性与电导
Magnetism and Electrical Conduction in Lightly-Doped Single-Layer High-$T_c$ Cuprate $\mathrm{La}_2\mathrm{CuO}_{4+δ}$
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中文总结 AI 辅助
通过对比不同掺杂水平的单层铜酸盐单晶，揭示轻掺杂La₂CuO₄+δ中Cu-O平面的本征磁性与电导特性，发现其反铁磁自旋关联在奈尔温度附近迅速发展。
中文摘要 AI 辅助
本文研究了轻掺杂单层铜酸盐La₂CuO₄+δ（简称LCO，空穴掺杂水平p=2δ≅0.03）单晶的磁化强度、电阻率随温度的变化关系，以及它们随磁场的变化，并与极低温掺杂区域p≲0.015的情况进行对比，以揭示同时呈现反铁磁（AF）和超导（SC）序的Cu-O平面的本征磁性与电导特性。在p≅0.03的SC LCO中，Cu位点的亚晶格磁矩及其AF耦合仅比莫特绝缘母体材料小约15%，表明Cu 3d电子的局域化仍然极强。此外，本文还报告，在SC LCO中，二维AF自旋关联从T*≅280K开始向奈尔温度TN=266K迅速发展，此时面外电阻率开始大幅下降，这可能是p≅0.03的SC单层铜酸盐在如此高温度下发生AF有序的原因。
英文摘要
The temperature dependences of magnetization and electrical resistivity as well as their magnetic field dependences have been examined in lightly-doped single-layer cuprate $\mathrm{La}_2\mathrm{CuO}_{4+δ}$ (LCO, hole-doping level $p \, (2δ) \cong 0.03$) single crystals, in comparison with those in the extremely low doping region of $p \lesssim 0.015$ to uncover the intrinsic magnetism and electrical conduction of the $\mathrm{Cu\text{-}O}$ plane that exhibits both antiferromagnetic (AF) and superconducting (SC) orders simultaneously. In $p \cong 0.03$ SC LCO, the sub-lattice moments on $\mathrm{Cu}$ sites and their AF couplings are only $\sim 15\,\%$ smaller than those of the Mott-insulator parent material, suggesting that the localization of $\mathrm{Cu}$ $3d$ electrons remains very strong. Furthermore, we report that in the SC LCO, two-dimensional AF spin correlations develop rapidly from $T^* \cong 280\text{ K}$ towards Néel temperature $T_{\mathrm{N}} = 266\text{ K}$, where the out-of-plane resistivity starts to decrease largely. This might be responsible for the AF ordering at such a high temperature in the SC single-layer cuprate with $p \cong 0.03$.
