Fig. 3.

Control of dislocations with topological tweezers. (A) (See also Movie S1.) Glide can be induced by shearing the lattice on either side of a dislocation. This corresponds to a stress represented schematically on the right. (B) (See also Movies S3 and S4.) A climb force applied by dilating the lattice on one side of the dislocation results in the fissioning of the dislocation into a pair which by its joint gliding motion moves in the climb direction of the original dislocation. (C) (See also Movie S2.) Fissioning of a pair of dislocations by shearing a defect-free region of the lattice beyond the elastic regime. (D) (See also Movie S6.) Opposing shear stresses trap a dislocation which can then be moved along its glide plane. (E) (See also Movie S7.) Application of a commensurate potential, aligned with one side of a grain over a grain boundary, is capable of moving the grain boundary.