A control method is proposed that controls inter-component phase difference solitons by using splitting or fusion caused by the interaction between inter-component phase difference solitons themselves, without the need for application of external energy. By using a line structure (10) in which an inter-component phase difference soliton propagation line through which an inter-component phase difference soliton (So) which can exist in a superconducting environment can travel is divided into a plurality of branch lines (10-1 and 10-2) at least at a branch end (Po) set in the middle of the line, an inter-component phase difference soliton (So) in a main line (10M) which is an undivided line portion is allowed to be split and to enter the plurality of branch lines (10-1 and 10-2) without a supply of external energy, or inter-component phase difference solitons (So1 and So2) in the respective branch lines (10-1 and 10-2) are fused together without a supply of external energy, whereby an inter-component phase difference soliton (So) is allowed to propagate through the main line (10M).