Challenge 1: Creating a Bell Pair

We saw on the first day that quantum entanglement can connect qubits across great distances. This special kind of connection is the basic building block for most quantum communication algorithms. Later in this module, we will see how to use this building block to solve some interesting problems. As a warm-up, we will start by writing a quantum circuit that creates an entangled Bell pair, starting from a pair of qubits in the |00⟩ state. We will also spend some time reflecting on what it really takes to make a Bell pair. The challenge outline is as follows.