Quantum Oscillations and the Quasiparticle Properties of Thin Film Sr${}_2$RuO${}_4$

Abstract

We measure the Shubnikov-de Haas effect in thin-film Sr${}_2$RuO${}_4$ grown on an (LaAlO${}_3$)${}_{0.29}$-(SrAl${}_{1/2}$Ta${}_{1/2}$O${}_3$)${}_{0.71}$ (LSAT) substrate. We detect all three known Fermi surfaces and extract the Fermi surface volumes, cyclotron effective masses, and quantum lifetimes. We show that the electronic structure is nearly identical to that of single-crystal Sr${}_2$RuO${}_4$, and that the quasiparticle lifetime is consistent with the Tc of comparably clean, single-crystal Sr${}_2$RuO${}_4$. Unlike single-crystal Sr${}_2$RuO${}_4$, where the quantum and transport lifetimes are roughly equal, we find that the transport lifetime is $1.3\pm 0.1$ times longer than the quantum lifetime. This suggests that extended (rather than point) defects may be the dominant source of quasiparticle scattering in these films. To test this idea, we perform cross-sectional STEM and find that out-of-phase boundaries extending the entire thickness of the film occur with a density that is consistent with the quantum mean free path. The long quasiparticle lifetimes make these films ideal for studying the unconventional superconducting state in Sr${}_2$RuO${}_4$ through the fabrication of devices -- such as planar tunnel junctions and SQUIDs.

arXiv comment12 pages, 8 figures

References in corpus (10)

• Pronounced drop of ${}^{17}$O NMR Knight shift in superconducting state of Sr${}_2$RuO${}_4$
• Hidden quasi one-dimensional superconductivity in Sr${}_2$RuO${}_4$
• Thermodynamic Evidence for a Two-Component Superconducting Order Parameter in Sr${}_2$RuO${}_4$
• A proposal for reconciling diverse experiments on the superconducting state in Sr2RuO4
• Strain Control of Fermiology and Many-Body Interactions in Two-Dimensional Ruthenates
• Momentum Resolved Superconducting Energy Gaps of Sr${}_2$RuO${}_4$ from Quasiparticle Interference Imaging
• Molecular beam epitaxy growth of superconducting Sr2RuO4 films
• Superconducting pairing in Sr${}_2$RuO${}_4$ from weak to intermediate coupling
• Shubnikov-de Haas quantum oscilations reveal a reconstructed Fermi surface near optimal doping in a thin film of the cuprate superconductor Pr${}_{1.86}$Ce${}_{0.14}$CuO${}_{4\pm \delta }$
• Quantum Oscillations and Overcritical Torque Interaction in Sr2RuO4

Cited by in corpus (1)

• Advances in Complex Oxide Quantum Materials Through New Approaches to Molecular Beam Epitaxy