Ancilla assisted Discrete Time Crystals in Non-interacting Spin Systems

We show here through experiments and exact analytical models the emergence of discrete time translation symmetry breaking in non-interacting systems. These time-periodic structures become stable against perturbations only in the presence of their interaction with the ancillary quantum system and display subharmonic response over a range of rotation angle errors. We demonstrate this effect for central spin and spin-mechanical systems, where the ancillary induced interaction among the spins stabilizes the spin dynamics against finite errors. Further, we extend these studies and show the possibility to even achieve non-local (remote) synchronization of such Floquet crystals.