Angle-resolved photoemission spectroscopy of superconducting (La,Pr)3Ni2O7/SrLaAlO4 heterostructures

Abstract

Ruddlesden-Popper bilayer nickelate thin film superconductors discovered under ambient pressure enable vast possibilities for investigating electronic structures of the superconducting state. Here, we report angle-resolved photoemission spectroscopy (ARPES) measurements of 1, 2, and 3 unit-cell epitaxial La2.85Pr0.15Ni2O7 films grown on SrLaAlO4 substates, through pure-oxygen in situ sample transportation. Evidence obtained using photons with distinct probing depths shows that conduction is localized primarily at the first unit cell near the interface. Scanning transmission electron microscopy (STEM), together with energy-dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS), indicates that interfacial Sr diffusion and pronounced p-d hybridization gradient may collectively account for the interfacial confinement of conduction. Fermi surface maps reveal hole doping compared to non-superconducting ambient-pressure bulk crystals. Measurements of dispersive band structures suggest the contributions from both Ni dx2-y2 and dz2 orbitals at the Fermi level. Density functional theory (DFT) + U calculations capture qualitative features of the ARPES results, consistent with a hole-doped scenario. These findings constrain theoretical models of the superconducting mechanism and suggest potential for enhancing superconductivity in nickelates under ambient pressure.

References in corpus (37)

• Angle-resolved photoemission spectroscopy of the cuprate superconductors
• Theory of Intertwined Orders in High Temperature Superconductors
• Superconductivity near 80 Kelvin in single crystals of La3Ni2O7 under pressure
• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Electronic structure of the parent compound of superconducting infinite-layer nickelates
• Energy gaps in high-transition temperature cuprate superconductors
• High-temperature superconductivity with zero-resistance and strange metal behavior in La${}_3$Ni${}_2$O${}_{7-\delta }$
• Bilayer two-orbital model of La${}_3$Ni${}_2$O${}_7$ under pressure
• Visualization of Oxygen Vacancies and Self-doped Ligand Holes in La3Ni2O7-δ
• Possible $S_{\pm }$-wave superconductivity in La${}_3$Ni${}_2$O${}_7$
• The s${}^{\pm }$-Wave Pairing and the Destructive Role of Apical-Oxygen Deficiencies in La${}_3$Ni${}_2$O${}_7$ Under Pressure
• Possible high $T_c$ Superconductivity in La${}_3$Ni${}_2$O${}_7$ under High Pressure through Manifestation of a Nearly-Half-Filled Bilayer Hubbard Model
• Interlayer Coupling Driven High-Temperature Superconductivity in La${}_3$Ni${}_2$O${}_7$ Under Pressure
• Correlated electronic structure of La${}_3$Ni${}_2$O${}_7$ under pressure
• Orbital-Dependent Electron Correlation in Double-Layer Nickelate La3Ni2O7
• Doping evolution of the Mott-Hubbard landscape in infinite-layer nickelates
• Bilayer $t$-$J$-$J_{\perp }$ Model and Magnetically Mediated Pairing in the Pressurized Nickelate La${}_3$Ni${}_2$O${}_7$
• Effective bi-layer model Hamiltonian and density-matrix renormalization group study for the high-Tc superconductivity in La${}_3$Ni${}_2$O${}_7$ under high pressure
• Electronic structure, dimer physics, orbital-selective behavior, and magnetic tendencies in the bilayer nickelate superconductor La${}_3$Ni${}_2$O${}_7$ under pressure
• Ambient-pressure superconductivity onset above 40 K in bilayer nickelate ultrathin films
• Structural phase transition, $s_{\pm }$-wave pairing and magnetic stripe order in the bilayered nickelate superconductor La${}_3$Ni${}_2$O${}_7$ under pressure
• High-$T_c$ superconductivity by mobilizing local spin singlets and possible route to higher $T_c$ in pressurized La${}_3$Ni${}_2$O${}_7$
• High Temperature Superconductivity in La${}_3$Ni${}_2$O${}_7$
• Electronic correlations and partial gap in the bilayer nickelate La${}_3$Ni${}_2$O${}_7$
• Charge Transfer and Zhang-Rice Singlet Bands in the Nickelate Superconductor $\mathrm{L}{\mathrm{a}}_3\mathrm{N}{\mathrm{i}}_2{\mathrm{O}}_7$ under Pressure
• Normal and superconducting properties of La${}_3$Ni${}_2$O${}_7$
• High-T${}_C$ superconductivity in $\mathrm{L}{\mathrm{a}}_3\mathrm{N}{\mathrm{i}}_2{\mathrm{O}}_7$ based on the bilayer two-orbital t-J model
• Unconventional crystal structure of the high-pressure superconductor La${}_3$Ni${}_2$O${}_7$
• Pressure Driven Fractionalization of Ionic Spins Results in Cupratelike High-$T_c$ Superconductivity in La${}_3$Ni${}_2$O${}_7$
• Superconductivity in nickelate and cuprate superconductors with strong bilayer coupling
• Long-Range Structural Order in a Hidden Phase of Ruddlesden-Popper Bilayer Nickelate La${}_3$Ni${}_2$O${}_7$
• Hund electronic correlation in La${}_3$Ni${}_2$O${}_7$ under high pressure
• Cuprate-like Electronic Structures in Infinite-Layer Nickelates with Substantial Hole Dopings
• Electronic Correlation and Pseudogap-like Behavior of High-Temperature Superconductor La3Ni2O7
• Electronic Structure of Superconducting Infinite-Layer Lanthanum Nickelates
• Electronic structure of Ruddlesden-Popper nickelates: strain to mimic the effects pressure
• Gigantic-oxidative atomic-layer-by-layer epitaxy for artificially designed complex oxides

Cited by in corpus (31)

• Correlated electronic structures and unconventional superconductivity in bilayer nickelate heterostructures
• Recent progress in nickelate superconductors
• Band Structure and Pairing Nature of La${}_3$Ni${}_2$O${}_7$ Thin Film at Ambient Pressure
• Superconductivity and Electronic Structures of Nickelate Thin Film Superstructures
• Reducing the strain required for ambient-pressure superconductivity in bilayer nickelates
• Impact of Pressure and Apical Oxygen Vacancies on Superconductivity in La${}_3$Ni${}_2$O${}_7$
• Superconducting gap structure and bosonic mode in La2PrNi2O7 thin films at ambient pressure
• Electronic structures and multi-orbital models of La${}_3$Ni${}_2$O${}_7$ thin films at ambient pressure
• Phase diagrams and two key factors to superconductivity of Ruddlesden-Popper nickelates
• Effective perpendicular electric field as a probe for interlayer pairing in ambient-pressure superconducting La${}_{2.85}$Pr${}_{0.15}$Ni${}_2$O${}_7$ thin films
• Superconducting Dome in ${\mathrm{La}}_{3-x}{\mathrm{Sr}}_x{\mathrm{Ni}}_2{\mathrm{O}}_{7-\delta }$ Thin Films
• Possible Liquid-Nitrogen-Temperature Superconductivity Driven by Perpendicular Electric Field in the Single-Bilayer Film of La${}_3$Ni${}_2$O${}_7$ at Ambient Pressure
• Strain-Engineered Electronic Structure and Superconductivity in La${}_3$Ni${}_2$O${}_7$ Thin Films
• Superconductivity governed by Janus-faced fermiology in strained bilayer nickelates
• Enhanced superconductivity in the compressively strained bilayer nickelate thin films by pressure
• Unifying Strain-driven and Pressure-driven Superconductivity in La${}_3$Ni${}_2$O${}_7$: Suppressed charge/spin density waves and enhanced interlayer coupling
• Stabilizing and Tuning Superconductivity in La${}_3$Ni${}_2$O${}_{7-\delta }$ Films: Oxygen Recycling Protocol Reveals Hole-Doping Analogue
• General trends of electronic structures, superconducting pairing, and magnetic correlations in the Ruddlesden-Popper nickelate $m$-layered superconductors La${}_{m+1}$Ni${}_m$O${}_{3m+1}$
• Nodeless superconducting gap and electron-boson coupling in (La,Pr,Sm)${}_3$Ni${}_2$O${}_7$ films
• Electronic reconstruction and interface engineering of emergent spin fluctuations in compressively strained La${}_3$Ni${}_2$O${}_7$ on SrLaAlO${}_4$(001)
• Unified mechanism of charge-density-wave and high-$T_c$ superconductivity protected from oxygen vacancies in bilayer nickelates
• Universal electronic structure of multi-layered nickelates via oxygen-centered planar orbitals
• Quantum phase transition driven by competing intralayer and interlayer hopping in bilayer nickelates
• Compressive Strain Turns $s^{\pm }$ into $d$-Wave Pairing in One-unit-cell La${}_3$Ni${}_2$O${}_7$ Thin Film Via Substrate-Induced Hole Doping
• Incommensurate spin fluctuations and competing pairing symmetries in La${}_3$Ni${}_2$O${}_7$
• Impact of multiband effects on non-Fermi-liquid transport phenomena in bilayer nickelates
• Theoretical study of the electronic correlation and superconducting pairing in La${}_{2.85}$Pr${}_{0.15}$Ni${}_2$O${}_7$ film grown on SrLaAlO${}_4$
• Progress of ambient-pressure superconductivity in bilayer nickelate thin films
• Strain-triggered high-temperature superconducting transition in two-dimensional carbon allotrope
• Bridging ambient- and high-pressure superconductivity in La${}_2$LnNi${}_2$O${}_7$ films
• Weak coupling theory of nickel-based 327 superconductors