Laser radiation control of the magnetic state of multilayer nanofilms

Physical mechanisms of magnetization reversal of multilayer magnetic nanofilms by laser radiation are examined and the experiments on the effect of the magnetic field and nanosecond and picosecond laser pulses on the conductivity of the Tb$_{19}$Co$_5$Fe$_{76}$/Pr$_6$O$_{11}$/Tb$_{22}$Co$_5$Fe$_{73}$ and Co$_{80}$Fe$_{20}$/Pr$_6$O$_{11}$/Co$_{30}$Fe$_{70}$ tunnel microcontacts are carried out. It is shown that with the help of such laser pulses, magnetization reversal of magnetic nanolayers is possible in a zero external magnetic field under the action of the spin current magnetic field, induced by the photon pressure of laser radiation, or the magnetic field generated by circularly polarized picosecond laser pulses. A relative change in the resistance upon the laser magnetization reversal of one of the nanolayers in the Co$_{80}$Fe$_{20}$/Pr$_6$O$_{11}$/Co$_{30}$Fe$_{70}$ microcontacts reaches a value of $\Delta R/R$ = 0.06 for $T$ = 300 K and $\Delta R/R$ = 0.25 for $T$ = 80 K, in the Tb$_{19}$Co$_5$Fe$_{76}$/Pr$_6$O$_{11}$/Tb$_{22}$Co$_5$Fe$_{73}$ microcontacts, $\Delta R/R$ = 0.3 for $T$ = 300 K and $\Delta R/R$ = 0.7 for $T$ = 80 K.