论文标题
磁性诱导的本地晶格异常和低频夜电波动中的莫特绝缘子LA $ _2 $ o $ $ _3 $ _3 $ _2 $ _2 $ _2 $ se $ _2 $
Magnetically-induced local lattice anomalies and low-frequency nematic fluctuations in the Mott insulator La$_2$O$_3$Fe$_2$Se$_2$
论文作者
论文摘要
我们报告了Mott绝缘子LA $ _2 $ o $ _3 $ Fe $ _2 $ _2 $ SE $ _2 $的研究，该研究是$^{139} $ LA核Quadrupole共振（NQR）。 NQR光谱证明了在磁磁相中的单个LA位点，而在抗磁磁有序相（néel温度$ t _ {\ rm {n}}} \ simeq 90 $ k）中，在抗磁磁有序相（néel温度$ t _ {\ rm {\ rm {n}} \ simeq 90 $ k）中证明了一个LA1和LA2。这两个位点的特征是不同的四极耦合，表明可能在域中隔离的不同晶格和/或电荷构型。四极耦合对LA2对温度的依赖性表明磁性参数驱动结构失真。核自旋晶格和横向松弛率，$ 1/t_1 $和$ 1/t_2 $，在顺磁相的证据波动，其特征频率远低于Heisenberg Exchange频率，这可能与列不合时宜的波动有关。
We report a study of the Mott insulator La$_2$O$_3$Fe$_2$Se$_2$ by means of $^{139}$La nuclear quadrupole resonance (NQR). The NQR spectra evidence a single La site in the paramagnetic phase and two inequivalent La sites, La1 and La2, in the antiferromagnetically-ordered phase (Néel temperature $T_{\rm{N}} \simeq 90$ K). These two sites are characterized by different quadrupole couplings, indicative of distinct lattice and/or charge configurations likely segregated in domains. The dependence of the quadrupole coupling for La2 on temperature suggests that the magnetic order parameter drives the structural distortion. The nuclear spin-lattice and transverse relaxation rates, $1/T_1$ and $1/T_2$, evidence fluctuations in the paramagnetic phase with characteristic frequencies well below the Heisenberg exchange frequency, likely associated with nematic fluctuations.
