Kreisel Andreas, Andersen Brian M, Rømer Astrid T, Eremin Ilya M, Lechermann Frank
Institut für Theoretische Physik, Universität Leipzig, D-04103 Leipzig, Germany.
Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark.
Phys Rev Lett. 2022 Aug 12;129(7):077002. doi: 10.1103/PhysRevLett.129.077002.
The discovery of superconductivity in infinite-layer nickelates has added a new family of materials to the fascinating growing class of unconventional superconductors. By incorporating the strongly correlated multiorbital nature of the low-energy electronic degrees of freedom, we compute the leading superconducting instability from magnetic fluctuations relevant for infinite-layer nickelates. Specifically, by properly including the doping dependence of the Ni d_{x^{2}-y^{2}} and d_{z^{2}} orbitals as well as the self-doping band, we uncover a transition from d-wave pairing symmetry to nodal s_{±} superconductivity, driven by strong fluctuations in the d_{z^{2}}-dominated orbital states. We discuss the properties of the resulting superconducting condensates in light of recent tunneling and penetration depth experiments probing the detailed superconducting gap structure of these materials.
无限层镍酸盐中超导电性的发现为迷人且不断发展的非常规超导体家族增添了一类新的材料。通过纳入低能电子自由度的强关联多轨道性质，我们从与无限层镍酸盐相关的磁涨落中计算出主导的超导不稳定性。具体而言，通过恰当地纳入Ni d_{x^{2}-y^{2}}和d_{z^{2}}轨道以及自掺杂带的掺杂依赖性，我们揭示了由d_{z^{2}}主导的轨道态中的强涨落驱动的从d波配对对称性到节点s_{±}超导性的转变。我们根据最近探测这些材料详细超导能隙结构的隧穿和穿透深度实验，讨论了所得超导凝聚体的性质。
