A compact realization of a reversible quantum n-to-2n decoder

This paper presents a compact realization of quantum n-to-2ⁿ decoder circuit, where n is the number of input bits. The proposed design of the quantum n-to-2ⁿ decoder circuit shows that it is composed of the quantum 2-to-4 decoder circuit. We present a quantum 2-to-4 decoder circuit using quantum Peres gate and CNOT quantum gates. Finally, we show an algorithm to construct a compact n-to-2ⁿ quantum decoder circuit. Our circuit performs better than the existing ones, e.g., the proposed 3-to-8 quantum decoder circuit improves 15.6% on the number of quantum gates, delay, area and power, 66.67% on garbage outputs and 25% on constant inputs than the Existing Design-2. We also simulate the proposed quantum decoder using Microwind DSCH 2.7 which shows the functional correctness of the circuit.