Elasticity-driven Nanoscale Texturing in Complex Electronic Materials

摘要

Finescale probes of many complex electronic materials have revealed anon-uniform nanoworld of sign-varying textures in strain, charge andmagnetization, forming meandering ribbons, stripe segments or droplets. Weintroduce and simulate a Ginzburg-Landau model for a structural transition,with strains coupling to charge and magnetization. Charge doping acts as alocal stress that deforms surrounding unit cells without generating defects.This seemingly innocuous constraint of elastic `compatibility', in fact inducescrucial anisotropic long-range forces of unit-cell discrete symmetry, thatinterweave opposite-sign competing strains to produce polaronic elasto-magnetictextures in the composite variables. Simulations with random local doping belowthe solid-solid transformation temperature reveal rich multiscale texturingfrom induced elastic fields: nanoscale phase separation, mesoscale intrinsicinhomogeneities, textural cross-coupling to external stress and magnetic field,and temperature-dependent percolation. We describe how this composite texturedpolaron concept can be valuable for doped manganites, cuprates and othercomplex electronic materials.