Qubits are NEVER both 0 and 1 simultaneously... they might be either at any given moment. Qubits are a vector in 3 dimensions of unit length, best illustrated with the Bloch Sphere[1] In this sphere Up, where Z=1 is written as |0> because of history.
One of the most common Quantum Logic Gates[2], the Hadamard gate performs a rotation of a diagonal axis half way between X and Z. This gate is used many, many times in Grover's algorithm
There are many such rotations in quantum computing. Error correction can only ensure that a state is at either end of an axis, not at the correct point anywhere on the sphere.
One of the most common Quantum Logic Gates[2], the Hadamard gate performs a rotation of a diagonal axis half way between X and Z. This gate is used many, many times in Grover's algorithm
There are many such rotations in quantum computing. Error correction can only ensure that a state is at either end of an axis, not at the correct point anywhere on the sphere.
[1] https://en.wikipedia.org/wiki/Bloch_sphere
[2] https://en.wikipedia.org/wiki/Quantum_logic_gate#Hadamard_ga...