HADAMARD TYPE OPERATIONS FOR QUBITS
Arpita Maitra, Preeti Parashar · International Journal of Quantum Information · 2006
We obtain the most general ensemble of qubits for which it is possible to design a universal Hadamard gate. These states, when geometrically represented on the Bloch sphere, give a new trajectory. We further consider some Hadamard "type" operations and find ensembles of states for which such transformations hold. The unequal superposition of a qubit and its orthogonal complement is also investigated.