For the first time, physicists in Italy have created a ‘lump soliton’: an extremely stable packet of light waves which can travel through 3D space, and even interact with other solitons without losing its shape.

Led by Ludovica Dieli at Sapienza University of Rome, the team achieved their result using a specially engineered crystal, whose responses to incoming light beams could be tightly controlled using an external voltage. Their study appears in Physical Review Letters.