Patent

Externally classical Fredkin gate device and operation method thereof, based on reversible quantum dynamics comprising: a control bit quantum dot (QDO), a first target bit quantum dot (QD1) and a second target bit quantum dot (QD2), and a Circuit configured for: applying a voltage to a first control contact (Bl) for preventing tunnel coupling between the control bit quantum dot and the first target bit quantum dot; applying a voltage to a second control contact (B2) for enabling tunnel coupling between the first target bit quantum dot and the second target bit quantum dot; applying voltage to biasing contacts (El, E2) for matching energy leveis and enable tunnelling between the first and the second target bit quantum dot when and only when the control bit is in the zero-charge State. The device comprises output contacts (QPCO, QPC1, QPC2). Also, an externally classical full adder with energetic advantage to existing devices.