Realization of an ultra-high magnetic field on a nano-scale

Abstract

In tunnel junctions of which at least one side is a ferromagnet, very large magnetic polarization change ($\approx 0.1{\mu }_B$) and splitting of the spin up and spin down Fermi energy ($\approx 0.1eV$) can be created under steady state finite current conditions (bias voltage $\approx$ 1 volt). This is {\bf much higher} than can be created by the highest magnetic field on earth. We illustrate this with a specific calculation of a recently observed very large Hall effect in the Al side of a Co-I-Al tunnel junction. Other recent experiments that support this idea are discussed.

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