Summary

In this chapter, you learned the difference between bits and qubits and how they are represented, both mathematically and visually. You also saw the difference between how single and multi-qubit systems are represented, including their mathematical representations, as well as how they are constructed and operated on. We also covered how to visualize the qubit as a Bloch sphere and a Qiskit sphere.

We now have the skills to represent the vector states of single and multi-qubits. We also understand the difference between representing multiple qubits as separate entities and as part of a complete system by using the tensor products of the qubits. This will help you to implement and operate the qubits on IBM Quantum devices.

In the next chapter, we will learn how to perform operations on single and multi-qubits and how those operations are triggered on the qubits of the real devices.