Quantum Soliton Collisions

Quantum Soliton Collisions are wave packets in which dispersion is balanced by nonlinearities and thus do not change shape. Either in optical or in matter-wave form, they thus hold promise for quantum technologies, particularly interferometry. Dr. Sebastian Wüster’s work focuses on the interactions of bright solitons in Bose-Einstein Condensates, motivated by experiments that indicate that these might not adhere to mean field theory. Simulations instead indeed show multiple quantum effects, causing solitons to collide predominantly repulsively after they have fragmented due to phase diffusion, which erases any meaning of their initial relative phase. In that state it is also likely for atoms to transfer from one soliton to the other during a collision, which subsequently causes solitons to hyper-entangle in momentum as well as atom number. The complex entangled post-collision state challenges existing criteria for hyper-entanglement of indistinguishable particles and when brought under control, the propensity of solitons to entangle in collisions can furnish a useful quantum resource.