Exploring multi-qubit quantum logic gates
In Chapter 2, Quantum Bits, Quantum Measurements, and Quantum Logic Gates, you learned about the most important single qubit quantum logic gates used frequently to construct quantum circuits. We will now dive into the multi-qubit quantum logic gates that help to form more complex quantum circuits. These are also used in various quantum algorithms. To begin, we will have a look at the CNOT gate.
The quantum CX or CNOT gate
The CNOT or the CX gate is one of the most important quantum gates utilized in quantum computing to create entanglement. The C in CNOT is known as Controlled. This gate is also known as a conditional bit flip gate because, as we will see, it flips the bit when a certain condition is met. This gate acts on two qubits, which can have quantum states 
and 
, where 
is the control qubit and 
is the target qubit. The target operation performed in this case is the X gate operation, which you learned about in Chapter 2, Quantum...
