Possible mechanisms of the external magnetic field influence on the exchange coupling

Possible mechanisms of the external magnetic field influence on exchange coupling in ultrathin M/N/M film structures are discussed. It is shown that the most reasonable mechanism is due to variation of the translational motion of spacer electrons in the external magnetic field. In this case in-plane components of the electron momentum should be quantized according to Landau levels. The most drastic effect should be observed in the case when magnetic field is perpendicular to the film plane. Comparison of calculations according to the proposed model with the experimental data is presented, showing very good correlation for the cases of presence and absence of external magnetic field.