Quantum Computing, Quantum Circuits, Quantum Computer, Quantum.
1/sqrt(2) (|0⟩ + |1⟩) H|1⟩ = |-⟩ = 1/sqrt(2) (|0⟩ -|1⟩) H|ψ⟩ = H(α|0⟩ + β|1⟩) = αH(|0⟩) + β H(|1⟩) = α|+⟩ + β |-⟩ = Check sum of square of coefficient of the result is also 1. Note: HH |ψ⟩ = |ψ⟩ Control Gates A Controlled Gate/ Operation/ Transform, say K, denoted by CK, applies the quantum gate K