Dynamical quantum phase transitions in a chiral p-wave superconductor upon chemical potential quenches

Dynamical quantum phase transitions (DQPTs) have been shown useful to identify non-trivial topology of quantum systems [1,2]. However, most of the preceding works do not incorporate self-consistency conditions for order parameters, which leads to periodic DQPTs.

Here, we study the dynamics of a two-dimensional chiral p-wave superconductor upon a quantum quench in the sign of the chemical potential within the BCS weak-coupling limit. We solve the BdG equations using fourth-order Runge-Kutta methods self-consistently and observe the phase of order parameter persistently oscillates sinusoidally in time after the quench. Despite the imposition of self- consistent conditions, periodic DQPTs are observed. These are identified as cusps in Loschmidt echo and accompanied by simultaneous creation of topological defects in the Pancharatnam geometric phase over curves in momentum space. We also discuss the robustness of the persistent phase oscillation against deformation of the Fermi surface and introduction of asymmetry to the chemical potential quenches.