C1000-112 - Mutiple Qubits and Entanglement

Multiple Qubits and Entanglement

On 22-May-2021, I continued to study Multiple Qubits and Entanglement.

This article starts with explanation for representing Multi-Qubit states. We are storing complex amplitudes in a vector. If we have 'n' qubits, we need to track 2^n Complex Amplitudes.  It is evident that these vectors grow exponentially as the number of qubits increases.

Here is a Qiskit code to demonstrate the 3 qubits and their state vectors

Let us see another example to represent single Qubit on Multi-Qubit statevector

What will happen if we apply gate to only one bit.  Here is the code and output

In the next code, we will see what will happen when we apply H gate followed by CNOT gate. YES.  We are going to see entangled state.

Histogram of above state is shown below

Bloch sphere representation of the above state is shown below

We can also view them as Q-Sphere visualization as shown below