In this section, we will examine the quantum versions of digital logic gates commonly used in classical computers. Before delving into the detailed exploration of this topic in subsequent sections, it is essential to highlight a crucial foundational concept:

• According to the fundamental principles of quantum computing, quantum operations are reversible, meaning that each operation can be undone. In contrast, classical computers typically rely on Boolean functions that are not inherently reversible. Therefore, to emulate digital operations in quantum computing, it is first necessary to construct reversible versions of these functions.

This distinction is one of the most significant differences between classical and quantum gates and forms a central idea of our study. In the following sections, we will explore the reasons and implications of these differences in greater detail, providing an in-depth analysis of the topic.