An impurity exact-diagonalization model places NdNiO2's NiO2 layers at a singlet-triplet crossover, with a cuprate-like singlet hole state and superexchange about ten times smaller than in cuprates.
The critical nature of the Ni spin state in doped NdNiO$_2$
1 Pith paper cite this work. Polarity classification is still indexing.
1
Pith paper citing it
abstract
Superconductivity with $T_c \approx 15K$ was recently found in doped NdNiO$_2$. The Ni$^{1+}$O$_2$ layers are expected to be Mott insulators so hole doping should produce Ni$^{2+}$ with $S=1$, incompatible with robust superconductivity. We show that the NiO$_2$ layers fall inside a ``critical'' region where the large $pd$ hybridization favors a singlet $^1\!A_1$ hole-doped state like in CuO$_2$. However, we find that the superexchange is about one order smaller than in cuprates, thus a magnon ``glue'' is very unlikely and another mechanism needs to be found.
citation-role summary
background 1
citation-polarity summary
fields
cond-mat.supr-con 1years
2019 1verdicts
CONDITIONAL 1roles
background 1polarities
support 1representative citing papers
citing papers explorer
-
The critical nature of the Ni spin state in doped NdNiO$_2$
An impurity exact-diagonalization model places NdNiO2's NiO2 layers at a singlet-triplet crossover, with a cuprate-like singlet hole state and superexchange about ten times smaller than in cuprates.