## Topological Magneto Electric Effect by Chern Structure in Strontium Ruthenate – Sr2RuO4

by Tommy on 26/11/2015http://arxiv.org/abs/1408.3614

Emergence of the Chern structure using Sr_{2}RuO_{4} nanofilms, Hiroyoshi Nobukane, Toyoki Matsuyama and Satoshi Tanda (6 August 2015)

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 angleθ=π/6 is determined by observing the topological magneto-electric effect in Sr_{2}RuO_{4}nanofilms.

**See also**: http://www.sciencedirect.com/science/article/pii/S0921452614008965

Topological electromagnetic response in the chiral superconductor Sr_{2}RuO_{4}, Hiroyoshi Nobukane, Toyoki Matsuyama and Satoshi Tanda, Physica B: Condensed Matter, 460, 168–170 (1 March 2015), doi:10.1016/j.physb.2014.11.062

We report the observation of a fractional topological magneto-electric effect in Sr

_{2}RuO_{4}single crystal thin films by measuring the electric transport properties. In the absence of an external magnetic field, the surface transport in Sr_{2}RuO_{4}thin films exhibited a fractional quantum Hall conductance in the superconducting state. The fractional magnetic-field-induced electric polarization was observed under zero bias current. We can understand the fractional quantum Hall conductance as a consequence of the observation of the (2+1) – dimensional topological surface state in the (3+1) – dimensional fractional topological magneto-electric effect in Sr_{2}RuO_{4}thin films.

So now I find out this prediction has already been confirmed by transport measurements.

Let the esoteric cosmic QCD axion physics era emerge!

**Up next**: mass, momentum and heat.

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