Abstract
We consider the ground states, excitations, and dynamics of a quasi-two-dimensional binary dipolar BoseEinstein condensate. Our focus is on the transition to a spin-stripe ground state in which the translational invariance is spontaneously broken by a striped immiscible pattern of the alternating components. We develop a ground-state phase diagram showing the parameter regime where the spin-stripe state occurs. Using Bogoliubov theory, we calculate the excitation spectrum and structure factors. We identify a balanced regime where the system has a Z2 symmetry, and in the spin-stripe state this yields a nonsymmorphic symmetry. We consider the evolution of the system following a quench from the uniform to spin-stripe state, revealing ordering dynamics involving defects of the stripe order. Using an order parameter to characterize the orientational order of the stripes, we show that the phase ordering exhibits dynamic scaling.