Spin-polarized tunneling spectroscopy in tunnel junctions with half-metallic electrodes

TL;DR

This study uses tunneling magnetoresistance measurements in junctions with half-metallic electrodes to analyze their electronic structure, providing detailed insights into the spin-dependent density of states and band gaps.

Contribution

It offers a quantitative method to determine the band structure and energy gaps of half-metallic electrodes using tunneling spectroscopy, advancing spin-resolved electronic characterization.

Findings

Determined the energy gap between Fermi level and minority spin band bottom.

Validated the band structure model with spin-polarized photoemission data.

Showed potential of magnetic tunnel junctions for spin-resolved spectroscopy.

Abstract

We have studied the magnetoresistance (TMR) of tunnel junctions with electrodes of La2/3Sr1/3MnO3 and we show how the variation of the conductance and TMR with the bias voltage can be exploited to obtain a precise information on the spin and energy dependence of the density of states. Our analysis leads to a quantitative description of the band structure of La2/3Sr1/3MnO3 and allows the determination of the gap delta between the Fermi level and the bottom of the t2g minority spin band, in good agreement with data from spin-polarized inverse photoemission experiments. This shows the potential of magnetic tunnel junctions with half-metallic electrodes for spin-resolved spectroscopic studies.