Topological defects in non-reciprocal active solids with odd elasticity

We study topological defects in active solids that violate Maxwell-Betti reciprocity (MBR). A solid violates MBR whenever its microscopic forces are nonconservative, i.e. they are not the gradient of a potential energy. In the continuum, broken MBR generically yields an asymmetric (or odd) elastic modulus tensor. We show that such a tensor modifies the strain and interaction between topological defects, for example reversing the stability of otherwise bound dislocation pairs. Such odd elastic moduli can also arise in systems with conservative microscopic forces if stress is present prior to deformation. Evading continuum theories, isolated dislocations can also become motile due to microscopic work cycles active at dislocation cores that compete with conventional Peach-Koehler forces caused, for example, by an ambient torque density. We perform molecular dynamics simulations isolating active plastic processes and discuss their experimental relevance to solids composed of spinning particles and robotic metamaterials.