Theory for Spin-Polarized Oscillations in Nonlinear Magneto-Optics due to Quantum Well States

TL;DR

This paper presents a theoretical study of spin-polarized oscillations in nonlinear magneto-optical effects caused by quantum well states in a layered film, revealing strong oscillations and their dependence on layer thickness.

Contribution

The authors develop a tight-binding model to predict spin-polarized quantum well oscillations in nonlinear magneto-optical Kerr effect, matching experimental observations.

Findings

Strong spin-polarized quantum well oscillations in NOLIMOKE.

Oscillation periods of 6-7 and 11 monolayers identified.

Enhanced effects due to Fe d states near Fermi level.

Abstract

Using an electronic tight-binding theory we calculate the nonlinear magneto-optical response from an x-Cu/1Fe/Cu(001) film as a function of frequency and Cu overlayer thickness (x=3 ... 25). We find very strong spin-polarized quantum well oscillations in the nonlinear magneto-optical Kerr effect (NOLIMOKE). These are enhanced by the large density of Fe $d$ states close to the Fermi level acting as intermediate states for frequency doubling. In good agreement with experiment we find two oscillation periods of 6-7 and 11 monolayers the latter being more pronounced.