We show that the pairing resonance in the Pauli-limited normal state of ultra-thin superconducting Al films provides a spin-resolved probe of conduction electron polarization in thin magnetic films. A superconductor-insulator-ferromagnet tunneling junction is used to measure the density of states in supercritical parallel magnetic fields that are well beyond the Clogston-Chandresekhar limit, thus greatly extending the field range of the tunneling density of states technique. The applicability and limitations of using the pairing resonance as a spin probe are discussed.
@article{arxiv.0907.1800,
title = {Measurement of Conduction Electron Polarization Via the Pairing Resonance},
author = {Y. M. Xiong and P. W. Adams and G. Catelani},
journal= {arXiv preprint arXiv:0907.1800},
year = {2009}
}