A quantum interference transistor may include a source; a drain; N channels (N≧2), between the source and the drain, and having N−1 path differences between the source and the drain; and at least one gate disposed at one or more of the N channels. One or more of the N channels may be formed in a graphene sheet. A method of manufacturing the quantum interference transistor may include forming one or more of the N channels using a graphene sheet. A method of operating the quantum interference transistor may include applying a voltage to the at least one gate. The voltage may shift a phase of a wave of electrons passing through a channel at which the at least one gate is disposed.