论文标题
Sr $ _2 $ ruo $ _4 $，例如掺杂的蛋饼和barium biSmuthate，是负电荷转移差距，甚至是奇偶校验超导体，$ \ frac {3} {4} {4} $ - 填充的氧气带
Sr$_2$RuO$_4$, like doped cuprates and barium bismuthate, is a negative charge-transfer gap even parity superconductor with $\frac{3}{4}$-filled oxygen band
论文作者
论文摘要
SR $ _2 $ ruo $ _4 $中超导性的综合理论必须解释实验，这些实验甚至暗示了平等超导顺序，而其他暗示时间逆转的对称性的实验。完整性进一步要求该理论适用于CA $ _2 $ ruo $ _4 $，这是一种莫特 - 哈伯半导体，它表现出由非常小的电场驱动的前所未有的绝缘体到金属过渡，也表现出浓度很小的电子，导致了金属的近距离偏远效力于Ferromagagnetsism。先前提出的用于超导粉结的价值过渡模型[Phys。 Rev. B {\ BF 98}，205153]扩展到SR $ _2 $ ruo $ _4 $和Ca $ _2 $ ruo $ _4 $。绝缘体到金属过渡与Mott-Hubbard半导体的简单熔化的预期不同。相反，ru离子在半导体中以低旋转ru $^{4+} $的形式出现，而金属中的高旋转ru $^{3+} $，价值过渡背后的驱动力是较低电荷状态下强的旋转电荷耦合，并导致大的旋转电荷耦合。金属和超导体鲜明烯是两个组件系统，其中半填充的高旋转ru $^{3+} $离子决定了磁性行为，但不能传输，而电荷载体完全在层氧气离子上，该层氧气离子的平均电荷为-1.5。旋转单线超导从相关的晶格中演变而来，仅折磨了3/4填充的层氧离子，与量子一致，许多身体计算都表明，在或非常接近这种填充物的超导配对相关相关性的超导对配对相关性的电子相互作用增强。修订版B {\ bf 93}，165110和{\ bf 93}，205111]。做出了几种特定模型的实验预测，包括由于SR $ _2 $ ruo $ _4 $，通过超导TC采取了sr $ _2 $ ruo $ _4 $。
A comprehensive theory of superconductivity in Sr$_2$RuO$_4$ must explain experiments that suggest even parity superconducting order and others that suggest broken time reversal symmetry. Completeness further requires that the theory applies to Ca$_2$RuO$_4$, a Mott-Hubbard semiconductor that exhibits an unprecedented insulator-to-metal transition driven by very small electric field, and also by doping with very small concentration of electrons, leading to a metallic state proximate to ferromagnetism. A valence transition model, previously proposed for superconducting cuprates [Phys. Rev. B {\bf 98}, 205153] is extended to Sr$_2$RuO$_4$ and Ca$_2$RuO$_4$. The insulator to metal transition is distinct from that expected from the simple melting of the Mott-Hubbard semiconductor. Rather, the Ru ions occur as low spin Ru$^{4+}$ in the semiconductor, and as high spin Ru$^{3+}$ in the metal, the driving force behind the valence transition being the strong spin-charge coupling and consequent large ionizaton energy in the low charge state. Metallic and superconducting ruthenates are two-component systems in which the half-filled high spin Ru$^{3+}$ ions determine the magnetic behavior but not transport, while the charge carriers are entirely on on the layer oxygen ions, which have an average charge -1.5. Spin singlet superconductivity evolves from the correlated lattice frustrated 3/4 filled band of layer oxygen ions alone, in agreement with quantum many body calculations that have demonstrated enhancement by electron-electron interactions of superconducting pair-pair correlations tions uniquely at or very close to this filling [Phys. Rev. B {\bf 93}, 165110 and {\bf 93}, 205111]. Several model specific experimental predictions are made, including that spin susceptibility due to Ru ions will remain unchanged as Sr$_2$RuO$_4$ is taken through superconducting Tc.
