Critical Nature of the Ni Spin State in Doped NdNiO2

f-Electron and Magnetic Ordering Effects in Nickelates LaNiO2 and NdNiO2: Remarkable Role of The Cuprate-Like 3dx2-y2 Band

“…These exchange parameters are half as large as those in La 2 CuO 4 [36] and larger than those estimated in Ref. [17]. The small J is consistent with the finding that the AFM gap is twice as large as in curpates, which in turn may be related to the larger value of Ni magnetic moments, which may be related to smaller Ni-d and O-p hybridization (larger ∆ dp ).…”

“…Recently, superconductivity in the hole-doped infinitelayer nickelate NdNiO 2 at 9∼15K has been reported in thin film samples grown on SrTiO 3 [7][8][9][10], although superconductivity in bulk NdNiO 2 has not been observed [11]. These results [7] have reinvigorated interest in searching for the microscopic mechanism of HTSC and stimulated many new open questions [10][11][12][13][14][15][16][17][18][19][20]. Notably, superconductivity is present both in hole-doped NdNiO 2 [7] and PrNiO 2 [21], but absent in LaNiO 2 [7].…”

“…In order to address these questions, a variety of theoretical studies have been performed, employing density functional theory (DFT) [14,18,[23][24][25], 'beyond' DFT methods, such as DFT+U [18,26,27], quasiparticle GW [28], dynamical mean-field theory (DMFT) [26,[29][30][31], and model Hamiltonians [15,17,26,32] that have been constructed to understand the low-energy physics.…”

Fluctuation-frustrated flat band instabilities in NdNiO2

“…A disparate variety of interacting models [1][2][3][4][5][6][7][8][9][10][11][12][13][14] based on density functional theory (DFT) studies [15][16][17][18][19][20][21][22] have been proposed to illuminate the electronic and magnetic behavior underlying the discovery [23] and experimental study [24][25][26] of long-sought superconductivity in a layered nickelate, specifically hole-doped NdNiO 2 (NNO). With the same infinite-layer structure as CaCuO 2 (CCO), which superconducts up to 110 K when doped [27], NNO displays several differences with CCO.…”

V4tetrahedral units inAV4X8lacunar spinels: Near degeneracy, charge fluctuations, and configurational mixing within a valence space of up to 21Hozoi1, Eldeeb2, Rößler3 2020Phys. Rev. Research8050View full textAdd to dashboardCite

“…In the solid-state context, such effects were earlier discussed at the quantum-chemical level for the cobalt-oxide perovskite LaCoO 3 [28], although in LaCoO 3 the essential interactions refer to one single transition-metal ion and the corresponding ligand octahedron, i. e., single-site d-d plus ligand-to-metal charge-transfer-type correlations, and the relative energy shifts are less spectacular, in the range of 1 eV. Another example for relevant electron correlations on a MO p unit is the recently discovered nickel-oxide superconductor Nd 0.8 Sr 0.2 NiO 2 [29], with p = 4 in the nickelate instead of p= 6 in LaCoO 3 . The present study draws attention to significantly more complex and therefore even more challenging physics occurring for clustered d ions (or clustered MX p units) in solids.…”