Intrinsic magnetism in superconducting infinite-layer nickelates

Nature Physics, Год журнала: 2022, Номер 18(9), С. 1043 - 1047

Опубликована: Авг. 1, 2022

Язык: Английский

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Universal orbital and magnetic structures in infinite-layer nickelates

Physical review. B./Physical review. B, Год журнала: 2024, Номер 109(2)

Опубликована: Янв. 19, 2024

We conducted a comparative study of the rare-earth infinite-layer nickelate films, $R{\mathrm{NiO}}_{2}$ ($R$ = La, Pr, and Nd), using resonant inelastic x-ray scattering (RIXS). found that gross features orbital configurations are essentially same, with minor variations in detailed hybridization. For low-energy excitations, we unambiguously confirm presence damped magnetic excitations all three compounds. By fitting to linear spin-wave theory, comparable spin exchange coupling strengths damping coefficients extracted, indicating universal structure nickelates. Interestingly, while signatures charge order observed ${\mathrm{LaNiO}}_{2}$ quasielastic region RIXS spectrum, it is absent ${\mathrm{NdNiO}}_{2}$ ${\mathrm{PrNiO}}_{2}$. This prompts further investigation into universality origins within

Язык: Английский

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Synthesis and physical properties of LaNiO2 crystals

Physical Review Materials, Год журнала: 2023, Номер 7(1)

Опубликована: Янв. 30, 2023

Infinite-layer (IL) nickelates are an emerging family of superconductors whose similarities and differences to cuprate under intense debate. To date, the IL phase can only be reached via topotactic oxygen reduction perovskite phase, using H$_2$ gas or reducing agents such as CaH$_2$. While method has been widely employed on thin film polycrystalline powder samples, La$_{1-x}$Ca$_x$NiO$_3$ single-crystals with lateral dimensions up 150 $\mu$m was achieved recently, indirect contact Here we report transformation much larger LaNiO$_3$ crystals more than one millimeter, direct We characterize crystalline, magnetic, electronic properties obtained LaNiO$_{2}$ by single-crystal x-ray diffraction (XRD), magnetometry, electrical transport, photoelectron spectroscopy (XPS) measurements. The amount incorporated hydrogen due process is determined a extraction method. In addition, investigate evolution lattice parameters hydrostatic pressure 12 GPa, high-resolution synchrotron XRD. Furthermore, provide comparison several physical their counterparts.

Язык: Английский

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Origin of a Topotactic Reduction Effect for Superconductivity in Infinite-Layer Nickelates

Physical Review Letters, Год журнала: 2024, Номер 133(6)

Опубликована: Авг. 8, 2024

Topotactic reduction utilizing metal hydrides as reagents has emerged an effective approach to achieve exceptionally low oxidization states of ions and unconventional coordination networks. This method opens avenues the development entirely new functional materials, with one notable example being infinite-layer nickelate superconductors. However, effect on atomic reconstruction electronic structures-crucial for superconductivity-remains largely unresolved. We designed two sets control Nd_{0.8}Sr_{0.2}NiO_{2} thin films used secondary ion mass spectroscopy highlight absence reduction-induced hydrogen intercalation. X-ray absorption revealed a significant linear dichroism dominant Ni 3d_{x2-y2} orbitals superconducting samples, indicating single-band nature nickelates. Consistent T_{c}, 3d asymmetry manifests domelike dependence duration. Our results unveil critical role in modulating Ni-3d orbital polarization its impact properties.

Язык: Английский

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Experimental Progress in Superconducting Nickelates

Annual Review of Condensed Matter Physics, Год журнала: 2023, Номер 15(1), С. 305 - 324

Опубликована: Дек. 6, 2023

The superconducting nickelates were first proposed as potential analogs to the cuprate unconventional superconductors in 1999, but it took twenty years before superconductivity was successfully stabilized epitaxial thin films. Since then, a flurry of both experimental and theoretical efforts have sought understand similarities differences between two systems how they manifest macroscopic normal state properties. Although cuprates indeed share many commonalities within their respective phase diagrams, several notable also emerged, especially regarding parent compounds, electronic hybridization, fermiology. Here, we provide survey rapidly developing landscape layered nickelate superconductors, including recent progress probe not just other ordered phases these compounds.

Язык: Английский

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Magnetic Properties and Pseudogap Formation in Infinite-Layer Nickelates: Insights From the Single-Band Hubbard Model

Frontiers in Physics, Год журнала: 2022, Номер 10

Опубликована: Фев. 21, 2022

We study the magnetic and spectral properties of a single-band Hubbard model for infinite-layer nickelate compound LaNiO$_2$. As spatial correlations turn out to be key ingredient understanding its physics, we use two complementary extensions dynamical mean-field theory take them into account: cellular vertex approximation. Additionally systematic analysis doping dependence non-Curie-Weiss behavior uniform susceptibility, provide insight relation formation pseudogap regime by calculation one-particle function correlation length. The latter is order few lattice spacings when opens, indicating strong-coupling in analogy cuprates.

Язык: Английский

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Spin fluctuations sufficient to mediate superconductivity in nickelates

Physical review. B./Physical review. B, Год журнала: 2024, Номер 109(23)

Опубликована: Июнь 12, 2024

Many mechanisms for unconventional superconductivity have been proposed, but actually proving which one is in charge challenging. Quite astonishingly, dynamical vertex approximation predict the superconducting phase diagram of novel nickelate superconductors, with microscopic origin being antiferromagnetic spin fluctuations. The authors compare fluctuations behind these calculations to experiment. again good agreement gives an overall coherent and complete picture, thus a high level confidence that nickelates indeed mediated by

Язык: Английский

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Investigation of Hydrogen Incorporations in Bulk Infinite-Layer Nickelates

Frontiers in Physics, Год журнала: 2022, Номер 10

Опубликована: Март 14, 2022

Infinite-layer (IL) nickelates are an emerging class of superconductors, where the Ni$^{1+}$ valence state in a square planar NiO$_2$ coordination can only be reached via topotactic reduction perovskite phase. However, this soft chemistry with hydrogenous reagents is still at stage rapid development, and there number open issues, especially considering possibility hydrogen incorporation. Here we study time dependence transformation LaNiO$_3$ to LaNiO$_2$ for powder samples x-ray diffraction gas extraction techniques. While content increases time, neutron shows no negative scattering crystal lattice. The extra appears confined grain boundaries or secondary-phase precipitates. average structure, possibly also physical properties, primary phase therefore not noticeably affected by residues created transformation.

Язык: Английский

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Microscopic theory of superconducting phase diagram in infinite-layer nickelates

Physical review. B./Physical review. B, Год журнала: 2022, Номер 106(3)

Опубликована: Июль 7, 2022

Since the discovery of superconductivity in infinite-layer nickelates RNiO$_2$ (R=La, Pr, Nd), great research efforts have been paid to unveil its underlying superconducting mechanism. However, physical origin intriguing hole-doped phase diagram, characterized by a dome sandwiched between two weak insulators, is still unclear. Here, we present microscopic theory for electronic structure from fundamental model-based perspective. We found that appearance insulator lightly and heavily regime dominated Mottness Hundness, respectively, exhibiting unique orbital-selective doping originated competition Hund interaction crystal field splitting. Moreover, can also be created "mixed" transition Mott-insulator Hund-induced insulator, exactly reproducing experimentally observed diagram. Our findings not only demonstrate orbital-dependent strong-correlation physics Ni 3$d$ states, but provide unified understanding diagram nickelates, which are distinct well-established paradigms cuprates iron pnictides.

Язык: Английский

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Topotactic hydrogen forms chains in ABO2 nickelate superconductors

Physical review. B./Physical review. B, Год журнала: 2023, Номер 107(16)

Опубликована: Апрель 10, 2023

Despite enormous experimental and theoretical efforts, obtaining generally accepted conclusions regarding the intrinsic magnetic electronic properties of superconducting nickelates remains exceptionally challenging. Experiments show a significant degree uncertainty, indicating hidden factors in synthesized films, which call for further investigations. One those is possibility intercalating hydrogen during chemical reduction process from $\mathrm{Nd}(\mathrm{La}){\mathrm{NiO}}_{3}$ to $\mathrm{Nd}(\mathrm{La}){\mathrm{NiO}}_{2}$ using ${\mathrm{CaH}}_{2}$. While has been detected samples, not much known about its distribution through crystal influence on environment. Here, we tendency toward formation one-dimensional chains infinite-layers ${\mathrm{LaNiO}}_{2}$ superconductors density-functional theory supplemented by dynamical mean-field theory. The such induces coexistence different oxidation states Ni competing phases, possibly explains recently observed charge order nickelate superconductors. Furthermore, it contributes difficulty synthesizing homogeneous determining their ground states. smoking gun detect excess flat phonon modes, are infrared active quite insensitive exact arrangement H atoms.

Язык: Английский

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