The semiconductor industry has been progressively researching various emerging technologies. The fast-evolving discipline of quantum computing utilizes quantum physics ideas to address more complex problems exponentially than the classical paradigm. The reversible logic application is emphasized for emerging nanotechnologies as it guarantees a near energy-free computation. The article’s introduction gives an easy-to-understand overview of why quantum computing and quantum circuit design are essential. A ‘quantum circuit,’ or set of operations known as quantum gates, is required to perform computations on a quantum computer. A quantum circuit’s scalability and efficiency depend highly on the selection of quantum gates. A list of the basic 1-qubit and 2-qubit quantum gates is provided, along with their characteristics. Further, design optimization techniques for enhancing quantum circuits and their benefits and challenges are described to develop optimal quantum circuits. Optimization aims to minimize the number of gates in a quantum circuit, as this lowers the quantum circuit’s depth or time steps and, thus, its delay and quantum cost. The optimization techniques will also lessen quantum error when the circuit is run in a real quantum processor.