Effects of different concentrations of topotactic hydrogen impurities on the electronic structure of nickelate superconductors

Physical review. B./Physical review. B, Journal Year: 2023, Volume and Issue: 108(15)

Published: Oct. 26, 2023

Infinite-layer nickelate superconductors have recently been discovered to share both similarities and differences with cuprate superconductors. Notably, the incorporation of hydrogen (H) through topotactic reduction has found play a critical role in their electronic structure and, consequently, superconductivity. In this study, we utilized theoretical approach combining density-functional theory impurity approximation design three characteristic multi-orbital Hubbard models representing low, moderate, high concentrations topotactic-hydrogen. Consistent experimental findings, our simulations revealed that low topotactic-hydrogen induce high-spin states ($S=1)$ are composed by holes at ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ ${d}_{{z}^{2}}$ orbitals consequently emergent intersite hopping between is unfavorable for Conversely, an optimal concentration 25% H aligns single Ni-${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ band picture superconductivity infinite-layer nickelates, demonstrating its beneficial effect on promoting superconducting behavior.

Language: Английский

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Magnetism in doped infinite-layer NdNiO2 studied by combined density functional theory and dynamical mean-field theory

Physical review. B./Physical review. B, Journal Year: 2022, Volume and Issue: 106(4)

Published: July 6, 2022

The recent observation of superconductivity in infinite-layer nickelates has brought intense debate on the established knowledge unconventional based cuprates. Despite many similarities, differ from cuprates characteristics, most notable one among which is magnetism. Instead a canonical antiferromagnetic Mott insulator as undoped cuprates, generally believed to arise upon doping, show no sign magnetic ordering experiments. Through combined density functional theory, dynamical mean-field and model study, we that although increased energy splitting between O-$p$ orbital Cu/Ni-$d$ ($\Delta_{dp}$) results larger moment nickelates, it also leads stronger antiferromagnetism/ferromagnetism competition, weaker exchange coupling. Meanwhile, self-doping effect caused by Nd-$d$ screens Ni. Janus-faced $\Delta_{dp}$ together give systematic understanding behavior explain experimental observations.

Language: Английский

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Kondo scattering in underdoped Nd1−xSrxNiO2 infinite-layer superconducting thin films

National Science Review, Journal Year: 2023, Volume and Issue: 10(11)

Published: April 25, 2023

The recent discovery of superconductivity in infinite-layer nickelates generates tremendous research endeavors, but the ground state their parent compounds is still under debate. Here, we report experimental evidence for dominant role Kondo scattering underdoped Nd1-xSrxNiO2 thin films. A resistivity minimum associated with logarithmic temperature dependence both longitudinal and Hall resistivities are observed samples before superconducting transition. At lower temperatures down to 0.04 K, become saturated, following prediction model. linear scaling behavior [Formula: see text] between anomalous conductivity text]is revealed, verifying at low temperature. effect weak (anti-)localization found be secondary. Our experiments can help clarifying basic physics

Language: Английский

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Competing incommensurate spin fluctuations and magnetic excitations in infinite-layer nickelate superconductors

Communications Physics, Journal Year: 2023, Volume and Issue: 6(1)

Published: May 3, 2023

Abstract The recently discovered infinite-layer nickelates show great promise in helping to disentangle the various cooperative mechanisms responsible for high-temperature superconductivity. However, lack of antiferromagnetic order pristine presents a challenge connecting physics cuprates and nickelates. Here, by using quantum many-body Green’s function-based approach treat electronic magnetic structures, we unveil presence many two- three-dimensional stripe instabilities that are shown persist across phase diagram LaNiO 2 . Our analysis indicates properties closer those doped cuprates, which host ground state, rather than undoped cuprates. computed longitudinal-spin, transverse-spin, charge spectra found contain an admixture contributions from localized itinerant carriers. Theoretically obtained dispersion excitations (spin-flip) is be good accord with results recent resonant inelastic X-ray scattering experiments. study gives insight into origin strong competition their relationship

Language: Английский

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Phase formation in hole- and electron-doped rare-earth nickelate single crystals

APL Materials, Journal Year: 2023, Volume and Issue: 11(8)

Published: Aug. 1, 2023

The recent discovery of superconductivity in hole-doped infinite-layer nickelates has triggered a great interest the synthesis novel nickelate phases, which have primarily been examined thin film samples. Here, we report high-pressure optical floating zone (OFZ) growth various perovskite and perovskite-derived rare-earth single-crystals, investigate effects hole-, electron-, self-doping. For hole-doping with Ca Sr, observe phase separations during process when substitution level 8% is exceeded. A similar trend emerges for electron-doping Ce Zr. Employing lower doping levels allows us to grow sizeable crystals phase, exhibit significantly different electronic magnetic properties than undoped parent compounds, such as decreased resistivity suppressed response. Our insights into doping-dependent formation resulting synthesized reveal limitations opportunities exploration manipulation states nickelates.

Language: Английский

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