Nonlinear emergent elasticity and structural transitions of a skyrmion crystal under uniaxial distortion

摘要: Emergent crystals are the periodic alignment of ``emergent particles,'' i.e., localized collective behavior atoms or their charges, spins, orbits. The elasticity these novel states matter suffering mechanical loads can be strikingly softer than that underlying material, showing great strain-mediated tunability. However, deformation and possible failure emergent under strong strain, vital for realizing related applications, hitherto unclear. Here we theoretically study nonlinear structural transitions a Skyrmion crystal (SkX) uniaxial distortion. Under moderate tension, SkX behaves like ductile with an exotic negative crossover elastic stiffness Poisson's ratio at appropriate conditions magnetic field. observe most six phase transitions, generating four thermodynamically metastable. We argue this nondestructive polymorphism is general feature any exposed to loads.