Broadband THz spectroscopy of the insulator-metal transition driven by coherent lattice deformation at the SmNiO3/LaAlO3 interface

Abstract

We investigate the non-equilibrium insulator-metal transition driven in a SmNiO3 thin film by coherent optical excitation of the LaAlO3 substrate lattice. By probing the transient optical properties over a broad frequency range (100 - 800 cm^-1), we analyze both the time dependent metallic plasma and the infrared optical phonon line shapes. We show that the light-induced metallic phase in SmNiO3 has the same carrier density as the equilibrium metallic phase. We also report that the LaAlO3 substrate acts as a transducer only at the earlier time delays, as the vibrations are driven coherently. No long-lived structural rearrangement takes place in the substrate. Finally, we show that the transient insulator-metal transition occurs both below and above the Néel temperature. We conclude that the supersonic melting of magnetic order measured with ultrafast x-rays is not the driving force of the formation of the metallic phase. We posit that the insulator metal transition may origin from the rearrangement of ordered charges at the interface propagating into the film.

arXiv comment12 pages, 3 figures

References in corpus (6)

• Heterointerface engineered electronic and magnetic phases of NdNiO3 thin films
• Origins of bad metal conductivity and the insulator-metal transition in the rare-earth nickelates
• Ultrafast strain engineering in complex oxide heterostructures
• Spatially resolved ultrafast magnetic dynamics launched at a complex-oxide hetero-interface
• Tunable Charge and Spin Order in PrNiO${}_3$ Thin Films and Superlattices
• Electronic Transitions in Strained SmNiO_3 Thin Films

Cited by in corpus (10)

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• Enhanced electron-phonon coupling in graphene with periodically distorted lattice
• Disentangling lattice and electronic contributions to the metal-insulator transition from bulk vs. layer confined RNiO${}_3$
• Sum-frequency excitation of coherent magnons
• Multiple supersonic phase fronts launched at a complex-oxide hetero-interface
• Large optical tunability from charge density waves in 1T-TaS${}_2$ under incoherent illumination
• A comparative study of nonequilibrium insulator-to-metal transitions in electron-phonon systems
• Probing photo-induced rearrangements in the NdNiO${}_3$ magnetic spiral with polarization-sensitive ultrafast resonant soft x-ray scattering
• Terahertz-driven ultrafast dynamics of rare-earth nickelates by controlling only the charge degree of freedom
• Elastic stripes formation at electronic transitions