Controlling local resistance via electric-field induced dislocations

Dislocations are one-dimensional (1D) topological line defects where the lattice deviates from the perfect crystal structure. The presence of dislocations transcends condensed matter research and gives rise to a diverse range of emergent phenomena [1-6], ranging from geological effects [7] to light emission from diodes [8]. Despite their ubiquity, to date, the controlled formation of dislocations is usually achieved via strain fields, applied either during growth [9,10] or retrospectively via deformation, e.g., (nano [11-14])-indentation [15]. Here we show how partial dislocations can be induced using local electric fields, altering the structure and electronic response of the material where the field is applied. By combining high-resolution imaging techniques and density functional theory calculations, we directly image these dislocations in the ferroelectric hexagonal manganite Er(Ti,Mn)O3 and study their impact on the local electric transport behaviour. The use of an electric field to induce partial dislocations is a conceptually new approach to the burgeoning field of emergent defect-driven phenomena and enables local property control without the need of external macroscopic strain fields. This control is an important step towards integrating and functionalising dislocations in practical devices for future oxide electronics.
20 pages, 7 figures