Spontaneous strain and magnetization in doped topological insulators with nematic and chiral superconductivity

We show that spontaneous strain and magnetization can arise in the doped topological insulators with a two-component superconducting vector order parameter. The details of the effects depend on the symmetry of the order parameter, whether it is nematic or chiral. The transition from the nematic state to the chiral one can be performed by application of a magnetic field, while the transition from the chiral state to the nematic is tuned by the external strain. These transitions are associated with a jump of the magnetic susceptibility and mechanical stiffness. Possible experimental observations of the predicted effects are discussed.