Efficient Design of Ternary Reversible T Flip-Flop Using Quantum Dot Cellular Automata

Abstract

Reversible logic circuits are an exciting solution for designing efficient sequential and combinational circuits. Reducing the size of transistors to nanoscale has created new challenges and issues in the field-effect transistor (FET) industry, so alternative technologies are needed. Quantum dot cellular automata (QCA) technology, reversibility, and multi-valued logic can reduce energy loss and occupied area in circuit design. QCA is a new method to design logic circuits in nanotechnology, emerging with nanoelectronics to make more comprehensive and complex logic circuits. In an irreversible logic system, some bits are erased when the system performs any computation, and this causes heat dissipation and energy loss. Using reversible ternary logic instead of previous technologies leads to better performance and saving more energy. In this paper, we proposed a design for ternary quantum dot cellular automata (TQCA) reversible T flip-flop. For the first time, we have proposed circuits that simultaneously combine ternary logic, reversibility, and implementation using ternary QCA technology. Reversible gates are the basis of a reversible circuit, which is implemented in this paper to create a TQCA Toffoli gate and reversible fan-out circuit as the fundamentals of TQCA T flip-flop. In general, T flip-flops are used to implement other more complex sequential circuits, such as counters. The area, delay, cost, and cell count of the proposed TQCA reversible T flip-flop design are compared with those of other related works in binary QCA technology. The occupied area of the proposed TQCA reversible T flip-flop is 0.06 µm2 which is %40 less than that of previous related works.