Generation and storage of 360° domain walls in planar magnetic nanowires

360° domain walls in planar magnetic nanowires are studied by micromagnetic simulations. It is shown that a nanowire loop with a shape-isotropic wall generator at one end and a shape-anisotropic wall stopper at the other end functions like a data storage stack: 360° domain walls are generated and pushed into stack under rotating field before overflow while popped out and annihilated when field rotating direction is inverted until underflow. The stack capacity is determined by total nanowire loop length. This simple nanowire structure can be integrated into magnetic circuits as an operation unit for 360° domain wall generation and storage.