Manipulating superconductivity in Sr<sub>2</sub>RuO<sub>4</sub> thin films through epitaxial strain
ORAL
Abstract
Pushing the van Hove singularity in the γ band of Sr2RuO4 towards the Fermi level can potentially raise the transition temperature, Tc, of this unconventional superconductor. To test this concept, we explore the effect of biaxial strains from –0.9% to +1.0% imposed by commensurate epitaxy on (NdAlO3)0.39—(SrAl1/2Ta1/2O3)0.61 (NSAT), NdGaO3, (LaAlO3)0.29—(SrAl1/2Ta1/2O3)0.71 (LSAT), LaGaO3, and SrTiO3 substrates on the superconducting Tc and upper critical field Hc2 of Sr2RuO4 thin films. These biaxial strain studies are distinct from and compliment the existing uniaxial strain studies on Sr2RuO4 single crystals. Mean free paths up to 144 nm are observed in Shubnikov-de Haas oscillation measurements on these thin films and Tcs range from 1 K to 1.8 K for films with similar residual resistivities. The measured mean free paths in combination with the coherence lengths, determined from upper critical field measurements, established that all films are superconducting in the clean limit.
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Presenters
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Hari Nair
- Cornell University
- Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University