Majorana spin current generation by dynamic strain

Majorana fermions that emerge on the surface of topological superconductors are charge neutral but can have higher-rank electric multipoles by allowing for time-reversal and crystalline symmetries. Applying the general classification of these multipoles, we show that the spin current of Majorana fermions is driven by spatially nonuniform dynamic strains on the surface of a 3D topological crystalline superconductor. We find that the frequency dependence of the Majorana spin current reflects the energy dispersion of Majorana fermions. Our results provide new dynamics of Majorana fermions characterized by crystalline and superconducting symmetries.