In superconductivity, the Lockin Effect refers to the preference of vortex phases to be positioned at certain points within cells of a crystal lattice of an organic superconductor.
Studies of the Vortex Phases in an Organic Superconductor
"Lockin Effect, Irreversibility Field, and Josephson Vortex Penetration Depth in κ-(ET)2Cu[N(CN)2]Br ", R. Giannetta N.H. Tea, F.A.B. Chaves, S. Rao, M.B. Salamon, A.M. Kini, H.H. Wang, U. Geiser, J.M. Schlueter, M.W. Trawick, J.C. Garland, Physica C 321, 207 (1999)