论文标题
$ \ MATHBF {Q} = \ MATHBF {0} $ centennialite cacu $ _3 $（od）$ _ 6 $ cl $ cl $ _2 $ _2 $ _2 $ 0.6D $ _2 $ o：a spin-1/2完美的Kagome AntiferMagnet and $ j_1 $ j_1 $ - $ J__2 $ -
$\mathbf{q}=\mathbf{0}$ long-range magnetic order in centennialite CaCu$_3$(OD)$_6$Cl$_2$$\cdot$0.6D$_2$O: A spin-1/2 perfect kagome antiferromagnet with $J_1$-$J_2$-$J_d$
论文作者
论文摘要
矿物百年纪念CACU $ _3 $（oh）$ _ 6 $ Cl $ _2 \ CDOT0.6 $ H $ _2 $ O的晶体和磁结构通过同步X射线衍射和中子衍射测量值（通过密度功能理论（DFT）和PSEUDEREMITION RENMITION INFARITION INSTIMITION RENMARMANTIMATION（PFF）（PEFF）（PEFF）（PEFF）（PEFF）（PEFF）（PEFF）。 cacu $ _3 $（oh）$ _ 6 $ cl $ _2 \ cdot0.6 $ h $ _2 $ _2 $ o o在$ p \ bar {3} m1 $ space group和cu $^{2+} $ ions形式的抗fiferromagagnetic $ j_1 $中。检测到Cu $^{2+} $和Ca $^{2+} $离子之间的网络障碍。 CaCu$_3$(OH)$_6$Cl$_2\cdot0.6$H$_2$O enters a magnetic long-range ordered state below $T_\text{N}=7.2$~K, and the $\mathbf{q}=\mathbf{0}$ magnetic structure with negative vector spin chirality is obtained.在0.3〜K处的订购矩抑制至$ 0.58（2）μ_\ text {b} $。我们的DFT计算表明存在抗Fiferromagnetic $ J_2 $和Ferromagnetic $ j_d $ superexchange耦合强度的耦合，该耦合将系统置于三个磁性订单的交叉路口（在经典级别上），并且旋转 - $ \ $ \ frac-frac {1} $ pffrg分析显示了统治之处。 $ \ mathbf {q} = \ Mathbf {0} $类型磁相关，与观察到的$ \ Mathbf {q} = \ MathBf {0} $ spin结构相符并表示近似。结果表明，该材料位于量子关键点附近，并且可以很好地实现$ J_1 $ - $ J_2 $ - $ J_D $ KAGOME ANTIFERROMAGNET。
Crystal and magnetic structures of the mineral centennialite CaCu$_3$(OH)$_6$Cl$_2\cdot0.6$H$_2$O are investigated by means of synchrotron x-ray diffraction and neutron diffraction measurements complemented by density functional theory (DFT) and pseudofermion functional renormalization group (PFFRG) calculations. CaCu$_3$(OH)$_6$Cl$_2\cdot0.6$H$_2$O crystallizes in the $P\bar{3}m1$ space group and Cu$^{2+}$ ions form a geometrically perfect kagome network with antiferromagnetic $J_1$. No intersite disorder between Cu$^{2+}$ and Ca$^{2+}$ ions is detected. CaCu$_3$(OH)$_6$Cl$_2\cdot0.6$H$_2$O enters a magnetic long-range ordered state below $T_\text{N}=7.2$~K, and the $\mathbf{q}=\mathbf{0}$ magnetic structure with negative vector spin chirality is obtained. The ordered moment at 0.3~K is suppressed to $0.58(2)μ_\text{B}$. Our DFT calculations indicate the presence of antiferromagnetic $J_2$ and ferromagnetic $J_d$ superexchange couplings of a strength which places the system at the crossroads of three magnetic orders (at the classical level) and a spin-$\frac{1}{2}$ PFFRG analysis shows a dominance of $\mathbf{q}=\mathbf{0}$ type magnetic correlations, consistent with and indicating proximity to the observed $\mathbf{q}=\mathbf{0}$ spin structure. The results suggest that this material is located close to a quantum critical point and is a good realization of a $J_1$-$J_2$-$J_d$ kagome antiferromagnet.
