Quantum Computing, Quantum Programming, Quantum Physics, Mathematics.
multiple qubits. When we had 1 qubit, there were only two possible outcomes when we measured a qubit: 0 and 1. So we used two ket vectors to describe a qubit: Now if I have two qubits, then when I measure the system, I could get four outcomes: 00, 01, 10 and 11. So I need to use 4 ket vectors to