Emergence of the Chern structure using Sr${}_2$RuO${}_4$ nanofilms

Abstract

We discovered a fractional Chern structure in chiral superconducting Sr${}_2$RuO${}_4$ nanofilms by employing electric transport. By using Sr${}_2$RuO${}_4$ single crystals with nanoscale thickness, a fractional Hall conductance was observed without an external magnetic field. The Sr${}_2$RuO${}_4$ nanofilms enhanced the superconducting transition temperature to about 3 K. We found an anomalous induced voltage with temperature and thickness dependence, and the switching behavior of the induced voltage appeared when we applied a magnetic field. We suggest that there was fractional magnetic-field-induced electric polarization in the interlayer. These anomalous results are related to topological invariance. The fractional axion angle $\theta =\pi /6$ is determined by observing the topological magneto-electric effect in Sr${}_2$RuO${}_4$ nanofilms.

14 pages, 3 figures

References in corpus (7)

• Non-Abelian Anyons and Topological Quantum Computation
• Topological Field Theory of Time-Reversal Invariant Insulators
• Fractional topological insulators in three dimensions
• Axion topological field theory of topological superconductors
• Evidence from Tunneling Spectroscopy for a Quasi-One Dimensional Origin of Superconductivity in Sr2RuO4
• Higher-Tc superconducting phase in Sr2RuO4 induced by uniaxial pressure
• Nodeless spin triplet superconducting gap in Sr2RuO4

Cited by in corpus (2)

• Co-appearance of superconductivity and ferromagnetism in a Ca${}_2$RuO${}_4$ nanofilm crystal
• Electronic and vibrational signatures of ruthenium vacancies in Sr${}_2$RuO${}_4$ thin films