Induced magnetic two-dimensionality by hole doping in the superconducting infinite-layer nickelate Nd1−xSrxNiO2

Abstract

To understand the superconductivity recently discovered in Nd0.8Sr0.2NiO2, we carried out LDA+DMFT (local density approximation plus dynamical mean-field theory) and magnetic force response calculations. The on-site correlation in Ni-3d orbitals causes notable changes in the electronic structure. The calculated temperature-dependent susceptibility exhibits the Curie-Weiss behavior, indicating the localized character of its moment. From the low-frequency behavior of self-energy, we conclude that the undoped phase of this nickelate is Fermi-liquid-like contrary to cuprates. Interestingly, the estimated correlation strength by means of the inverse of quasi-particle weight is found to increase and then decrease as a function of hole concentration, forming a dome-like shape. Another remarkable new finding is that magnetic interactions in this material become two-dimensional by hole doping. While the undoped NdNiO2 has the sizable out-of-plane interaction, hole dopings strongly suppress it. This two-dimensionality is maximized at the hole concentration δ ≈ 0.25. Further analysis as well as the implications of our new findings are presented. arXiv:1909.05824v2 [cond-mat.supr-con]

Role of 4f states in infinite-layer NdNiO2

“…The inferred mean free path in a Fermi liquid inspired Bloch-Boltzmann treatment would be atomic size, meaning incoherent transport and a washed out FS. A dynamical mean field approximation treatment of Ni 3d fluctuations [11] in LaNiO 2 found little shifting and broadening of bands around E F , and no mechanism for the high resistivity. The large residual resistivity may be the result of the topotactic synthesis technique, with indications to be learned between the similarities and the distinctions between the doped thin films and doped bulk materials, [35] which also have similarly high residual resistivity.…”

“…A number of groups recently have revisited this question, with the objective of few-band model-building to quantify differences related to superconductivity. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] The popular approach has been to obtain the non-magnetic local density approximation (LDA) band structure of NdNiO 2 with the 4f 3 electrons assigned to a non-magnetic core, then approximate the low energy bands with a minimal local orbital model, add a repulsive local interaction, and * Electronic address: mckwan@korea.ac.kr † Electronic address: wepickett@ucdavis.edu evaluate the consequences, viz. the pairing susceptibility.…”

Ab initio many-body GW correlations in the electronic structure of LaNiO2

“…When it comes to the quasiparticle weight Z associated with this band, GW yields an almost constant Z GW = 0.70 ± 0.02 all along the Brillouin zone, whereas in Ref. 22 variation and is considerably reduced at Γ and along Γ-Z-R. Z is also rather constant in Ref. [24], but here a lower/upper Hubbard band splitting is clearly visible, unlike in Ref.…”

“…Finally, we compare our ab initio GW electronic structure with recently reported dynamical mean-field theory (DMFT) calculations [22][23][24]. Note that GW is an approximation to the exact solution, while DMFT relies on a Hubbard model (with the U term on the Ni 3d electrons only in the case of Ref.…”

“…To make further progress it is therefore important to establish how these features are affected by electronic correlations. Attempts in this direction were carried out within dynamical mean-field theory (DMFT) [22][23][24].…”