The basic building blocks of quantum computing are quantum gates and operations, which enable the manipulation and modification of qubits, the quantum bits utilized in quantum information processing. Comparable to conventional logic gates, quantum gates use quantum operations on qubits to make use of superposition and entanglement's special features. These gates are unique because, unlike classical logic gates, they are actually reversible; as in we can revert the new state of a qubit into an older one, or revert the change in a value. Let's get into more detail about quantum gates and their functions.
Quantum States and Quantum Gates
In quantum computing, a quantum state vector that can be in a superposition of the base states |0| and |1| is used to describe the state of a qubit. The mathematical operations known as quantum gates change the quantum state of one or more qubits. Quantum gates operate on the qubit states in a similar way to classical logic gates, but they also employ quantum features like superposition and entanglement to carry out more complex calculations. As seen in Fig.4 below, we can utilize matrices(usually 2x2) to represent a quantum gate, where the action of the gate is determined by multiplying the gate by the vector of the quantum state. This involves typical matrix manipulation, multiplying each node and element within it, or changing it in other ways through addition, and unit vectors. The Pauli-X gate is extremely simple operand, which just flips the qubit from 0 to 1 if it's 0, and flips from 1 to 0 if it's 1.