← Back to search

Measurement of the spin polarization of the magnetic semiconductor EuS with zero-field and Zeeman-split Andreev reflection spectroscopy

Cong Ren, J. Trbovic, R. L. Kallaher, J. G. Braden, J. S. Parker, S. von Molnár, P. Xiong

DOI 10.1103/PhysRevB.75.205208 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We report measurements of the spin polarization (P) of the concentrated magnetic semiconductor EuS using both zero-field and Zeeman-split Andreev reflection spectroscopy (ARS) with EuS∕Al planar junctions. The zero-field ARS spectra are well described by the modified (spin-polarized) Blonder-Tinkham-Klapwijk (BTK) model with expected superconducting energy gap and actual measurement temperature (no additional spectral broadening). The fittings consistently yield P close to 80% regardless of the barrier strength. Moreover, we performed ARS in the presence of a Zeeman splitting of the quasiparticle density of states in Al. To describe the Zeeman-split ARS spectra, we develop a theoretical model which incorporates the solution to the Maki-Fulde equations into the modified BTK analysis. The method enables the determination of the magnitude as well as the sign of P with ARS, and the results are consistent with those from the zero-field ARS. The experiments extend the utility of field-split superconducting spectroscopy from tunnel junctions to Andreev junctions of arbitrary barrier strengths.

Source-reported materials — not catalogue approval

FormulaReported Tc (K)Pressure (GPa)Type
Al

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

—Pressure not reportedunknown

Similar papers