论文标题
$ d+ig $ $ superpoductivity方案的多型均值场理论sr $ _2 $ ruo $ _4 $
Multiband mean-field theory of the $d+ig$ superconductivity scenario in Sr$_2$RuO$_4$
论文作者
论文摘要
许多看似矛盾的实验发现，关于Sr $ _2 $ _2 $ ruo $ _4 $的超导状态可以根据$（d_ {4h}）在$（d_ {4h}）$（d_ {4h}）$ symmetry symetry of Crystal的情况下，可以考虑到彼此之间的两种配对模式之间的猜想意外退化：A $ D_ $（b_ {1g}）$和$ g_ {xy（x^2-y^2）} $ - wave $（a_ {2g}）$超导状态。在本文中，我们提出了一种通用的多波段模型，其中涉及$ xz $和$ yz $ orbitals的$ g $ - 波配对来自第二个最邻居的互动。即使在$ d+ig $状态下打破了时间逆转对称性，这种超导体与bogoliubov fermi表面保持无间隙，该表面近似于A（垂直）线节点。该模型引起了临界温度$ T_C $与时间反转对称温度$ t_ \ text {trsb} $之间的分裂，这与SR $ _2 $ _2 $ ruo $ _4 $中的某些实验观察在质量上相似。
Many seemingly contradictory experimental findings concerning the superconducting state in Sr$_2$RuO$_4$ can be accounted for on the basis of a conjectured accidental degeneracy between two patterns of pairing that are unrelated to each other under the $(D_{4h})$ symmetry of the crystal: a $d_{x^2-y^2}$-wave $(B_{1g})$ and a $g_{xy(x^2-y^2)}$-wave $(A_{2g})$ superconducting state. In this paper, we propose a generic multi-band model in which the $g$-wave pairing involving the $xz$ and $yz$ orbitals arises from second-nearest-neighbor interactions. Even if time-reversal symmetry is broken in a $d+ig$ state, such a superconductor remains gapless with a Bogoliubov Fermi surface that approximates a (vertical) line node. The model gives rise to a strain-dependent splitting between the critical temperature $T_c$ and the time-reversal symmetry-breaking temperature $T_\text{trsb}$ that is qualitatively similar to some of the experimental observations in Sr$_2$RuO$_4$.
