Persuant to all contributors, here I will use a coin toss analogy since the vector direction is either up or down (heads or tails). Two coins will be used for each of two tosses. It's assumed that the process will be one-shot (shots=1).
Toss one: Superposition will be applied using Hadamard gates on two qubits. Collapse will result in the following possible binary results: [00,01,10,11] (HH,HT,TH,TT).
For toss two: Of the four binary results of toss one, I will choose either 00 or 11.
I want to know how to prepare two qubits in an entangled state after either 00 or 11 is measured on those two independent qubits prepared with Hadamards in toss one.