We use single crystal ⁶³Cu NMR techniques to revisit the early ⁶³Cu NQR signature of charge order observed for La_1.875Ba_0.125CuO₄ (T_c = 4 K) [A. W. Hunt et al., Phys. Rev. Lett. 82, 4300 (1999)]. We show that the growth of spin correlations is accelerated below ∼80 K, where the inverse Laplace transform (ILT) T₁ analysis of the ¹³⁹La NMR spin–lattice relaxation curve recently uncovered emergence of the slow components in the lattice and/or charge fluctuations [P. M. Singer et al., Phys. Rev. B 101, 174508 (2020)]. From the accurate measurements of the ⁶³Cu NMR signal intensity, spin echo decay M(2τ), spin–lattice relaxation rate ⁶³1/T₁, and its density distribution function P(⁶³1/T₁), we also demonstrate that charge order at T_charge \( \simeq \) 54 K turns on strong enhancement of spin fluctuations within charge ordered domains, thereby making the CuO₂ planes extremely inhomogeneous. The charge ordered domains grow quickly below T_charge, and the volume fraction F_CA of the canonical domains unaffected by charge order gradually diminishes by ∼35 K. This finding agrees with our independent estimations of F_CA based entirely on the ¹³⁹La ILTT₁ analyses, but is in a stark contrast with much slower growth of charge ordered domains observed for La_1.885Sr_0.115CuO₄ from its T_charge \( \simeq \) 80 K to T_c \( \simeq \) 30 K.

中文翻译：

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重新审视La1.875Ba0.125CuO4中电荷顺序的63Cu NMR特征

我们使用单晶⁶³ Cu NMR技术重现了La _1.875 Ba _0.125 CuO ₄（T _c = 4 K）观察到的电荷顺序的早期⁶³ Cu NQR签名[AW Hunt等，Phys。牧师 82，4300（1999）]。我们表明，自旋相关性的增长在〜80 K以下加速，其中¹³⁹ La NMR自旋-晶格弛豫曲线的逆拉普拉斯变换（ILT）T ₁分析最近发现了晶格和/或电荷中慢速成分的出现。波动[PM Singer等人，Phys。版本B 101，174508（2020）]。从⁶³的准确测量Cu NMR信号强度，自旋回波衰减M（2τ），自旋-晶格弛豫速率⁶³ 1 / T ₁及其密度分布函数P（⁶³ 1 / T ₁），我们还证明了T_电荷的电荷顺序 \（\ simeq \）54 K开启了电荷有序域内自旋涨落的强烈增强，从而使CuO ₂平面极为不均匀。电荷有序域在T_电荷以下快速增长，不受电荷阶数影响的规范域的体积分数F _CA逐渐减小约35K。这一发现与我们完全基于¹³⁹ La ILTT ₁分析得出的F _CA独立估计相符。，但与La _1.885 Sr _0.115 CuO ₄从其T观察到的电荷有序域的增长要慢得多_收费 \（\ simeq \）80 K为T _c \（\ simeq \） 30K。