Ya. Izyumov et al., Multicritical behavior of the phase diagrams of ferromagnet/superconductorlayered structures, JETP LETTER, 71(4), 2000, pp. 138-143
For ferromagnet/superconductor (F/S) layered structures, new 3D Larkin-Ovch
innikov-Fulde-Ferrell (LOFF) states are predicted. In most cases, these sta
tes are characterized by a higher critical temperature T-c than the known 1
D LOFF states. It is shown that the nonmonotonic behavior of T-c is determi
ned by the oscillations of the Cooper pair flux through the F/S boundary, w
hich occur as a result of the 3D-1D-3D phase transitions at the Lifshits tr
iple points. The appearance of the new 3D LOFF states and the presence of n
onmagnetic impurities leads to a strong damping of the 1D oscillations of t
he LOFF pair amplitude and to a considerable smoothing of the dependence of
T-c on the F layer thickness d(f). An interpretation of the behavior of th
e experimental dependences T-c(d(f)) obtained for F/S structures is propose
d. (C) 2000 MAIK "Nauka/Interperiodica".