Signatures of superconductivity near 80 K in a nickelate under high pressure

Nature, Journal Year: 2023, Volume and Issue: 621(7979), P. 493 - 498

Published: July 12, 2023

Language: Английский

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Bilayer Two-Orbital Model of La3Ni2O7 under Pressure

Physical Review Letters, Journal Year: 2023, Volume and Issue: 131(12)

Published: Sept. 20, 2023

The newly discovered Ruddlesden-Popper bilayer ${\mathrm{La}}_{3}{\text{Ni}}_{2}{\mathrm{O}}_{7}$ reaches a remarkable superconducting transition temperature ${T}_{c}\ensuremath{\approx}80\text{ }\text{ }\mathrm{K}$ under pressure of above 14 GPa. Here we propose minimal two-orbital model the high-pressure phase ${\mathrm{La}}_{3}{\text{Ni}}_{2}{\mathrm{O}}_{7}$. Our is constructed with Ni-$3{d}_{{x}^{2}\ensuremath{-}{y}^{2}}$, $3{d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ orbitals by using Wannier downfolding density functional theory calculations, which captures key ingredients material, such as band structure and Fermi surface topology. There are two electron pockets, $\ensuremath{\alpha}$, $\ensuremath{\beta}$, one hole pocket, $\ensuremath{\gamma}$, on surface, in $\ensuremath{\beta}$ pockets show mixing orbitals, while $\ensuremath{\gamma}$ pocket associated $\mathrm{Ni}\text{\ensuremath{-}}{d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ orbital. random approximation spin susceptibility reveals magnetic enhancement ${d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ state. A higher energy $\mathrm{O}\text{\ensuremath{-}}p$ also provided for further study.

Language: Английский

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Emergence of High-Temperature Superconducting Phase in Pressurized La₃Ni₂O₇ Crystals

Chinese Physics Letters, Journal Year: 2023, Volume and Issue: 40(11), P. 117302 - 117302

Published: Oct. 1, 2023

The recent report of pressure-induced structural transition and signature superconductivity with T c ≈ 80 K above 14 GPa in La 3 Ni 2 O 7 crystals has garnered considerable attention. To further elaborate this discovery, we carried out comprehensive resistance measurements on grown an optical-image floating zone furnace under oxygen pressure (15 bar) using a diamond anvil cell (DAC) cubic (CAC), which employ solid (KBr) liquid (glycerol) pressure-transmitting medium, respectively. Sample 1 measured the DAC exhibits semiconducting-like behavior large at low pressures gradually becomes metallic upon compression. At P ⩾ 13.7 observed appearance drop as much ∼ 50% around 70 K, evolves into kink-like anomaly 40 shifts to lower temperatures increasing magnetic field. These observations are consistent mentioned above. On other hand, sample CAC retains investigated range up 15 GPa. hump-like 130 ambient disappears In 11–15 gradual development shoulder-like temperatures, pronounced 98% below 62 GPa, reaching temperature-independent 20 μΩ K. Similarly, can be progressively shifted by applying external fields, resembling typical superconducting transition. Measurements reproduce 10 realize zero even though unusual is retained normal state. Based these results, constructed dome-shaped phase diagram discuss some issues regarding sample-dependent behaviors high-temperature crystals.

Language: Английский

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Correlated Electronic Structure of La3Ni2O7 under …

Physical Review Letters, Journal Year: 2023, Volume and Issue: 131(20)

Published: Nov. 15, 2023

Recently, superconductivity with a T_{c} up to 78 K has been reported in bulk samples of the bilayer nickelate La_{3}Ni_{2}O_{7} at pressures above 14 GPa. Important theoretical tasks are formulation relevant low-energy models and clarification normal state properties. Here, we study correlated electronic structure high-pressure phase four-orbital subspace using different many-body approaches: GW, dynamical mean field theory (DMFT), extended DMFT (EDMFT) GW+EDMFT, realistic frequency-dependent interaction parameters. The nonlocal correlation screening effects captured by GW+EDMFT result an instability toward formation charge stripes, 3d_{z^{2}} as main active orbital. We also comment on potential relevance rare-earth self-doping pocket, since hole doping suppresses ordering tendency.

Language: Английский

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s± -Wave Pairing and the Destructive Role of Apical-Oxygen Deficiencies in La3Ni

Physical Review Letters, Journal Year: 2023, Volume and Issue: 131(23)

Published: Dec. 5, 2023

Recently, the bilayer perovskite nickelate ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ has been reported to show evidence of high-temperature superconductivity (SC) under a moderate pressure about 14 GPa. To investigate superconducting mechanism, pairing symmetry, and role apical-oxygen deficiencies in this material, we perform random-phase approximation based study on model consisting ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ ${d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ orbitals Ni atoms both pristine crystal with deficiencies. Our analysis reveals an ${s}^{\ifmmode\pm\else\textpm\fi{}}$-wave symmetry driven by spin fluctuations. The crucial lies that it induces emergence $\ensuremath{\gamma}$ pocket, which is involved strongest Fermi-surface nesting. We further found local moments vicinity deficiencies, significantly suppresses ${T}_{c}$. Therefore, possible enhance ${T}_{c}$ eliminating oxygen during synthesis samples.

Language: Английский

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Electronic structure, dimer physics, orbital-selective behavior, and magnetic tendencies in the bilayer nickelate superconductor La3Ni2O7 under pressure

Physical review. B./Physical review. B, Journal Year: 2023, Volume and Issue: 108(18)

Published: Nov. 28, 2023

The recently discovered high-temperature superconductor La${}_{3}$Ni${}_{2}$O${}_{7\phantom{\rule{0.333em}{0ex}}}$ with ${T}_{c}$ ~ 80 K under pressure has revolutionized the field of correlated electrons. authors find here that an orbital-selective spin-singlet ``dimer'' linking two planes this bilayer via ${d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ orbital provides primary building block to study its electronic properties. Furthermore, in-plane robust interorbital hopping between ${e}_{g}$ states, competes more natural intraorbital hopping, leading a dominant spin stripe ($\ensuremath{\pi}$, 0) order, as well rich phase diagram.

Language: Английский

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High-temperature superconductivity with zero resistance and strange-metal behaviour in La3Ni2O7−δ

Nature Physics, Journal Year: 2024, Volume and Issue: 20(8), P. 1269 - 1273

Published: June 6, 2024

Language: Английский

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Visualization of oxygen vacancies and self-doped ligand holes in La3Ni2O7−δ

Nature, Journal Year: 2024, Volume and Issue: 630(8018), P. 847 - 852

Published: June 5, 2024

Language: Английский

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Correlated electronic structure, orbital-selective behavior, and magnetic correlations in double-layer La3Ni2O7 under pressure

Physical review. B./Physical review. B, Journal Year: 2023, Volume and Issue: 108(12)

Published: Sept. 5, 2023

Using ab initio band structure and $\mathrm{DFT}+\mathrm{dynamical}$ mean-field theory methods we examine the effects of electron-electron interactions on normal state electronic structure, Fermi surface, magnetic correlations recently discovered double-layer perovskite superconductor ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ under pressure. Our results suggest formation a negative charge transfer mixed-valence with Ni valence close to $1.75+$. We find remarkable orbital-selective renormalization $3d$ bands, ${m}^{*}/m\ensuremath{\sim}3$ 2.3 for $3{z}^{2}\text{\ensuremath{-}}{r}^{2}$ ${x}^{2}\text{\ensuremath{-}}{y}^{2}$ orbitals, respectively, in agreement experimental estimates. $k$-dependent spectral functions surfaces show significant incoherence states, implying proximity states orbital-dependent localization. Based our analysis static susceptibility, propose possible spin (or bond) density wave stripe high-pressure ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$.

Language: Английский

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Orbital-dependent electron correlation in double-layer nickelate La3Ni2O7

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: May 23, 2024

Abstract The latest discovery of high temperature superconductivity near 80 K in La 3 Ni 2 O 7 under pressure has attracted much attention. Many proposals are put forth to understand the origin superconductivity. determination electronic structures is a prerequisite establish theories nickelates but still lacking. Here we report our direct measurement by high-resolution angle-resolved photoemission spectroscopy. Fermi surface and band observed compared with structure calculations. Strong electron correlations revealed which orbital- momentum-dependent. A flat formed from Ni-3d $${}_{{z}^{2}}$$ z2 orbitals around zone corner ~ 50 meV below level exhibits strongest correlation. In many theoretical proposals, this expected play dominant role generating . Our observations provide key experimental information

Language: Английский

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