Controllability of Qubits
There are many properties a qubit should have to be considered a good or useful qubit. The most essential of these properties is controllability. To do meaningful qubits computations, one should always be able to have perfect control over the state of the qubits.
Further thinking
In the video, Jason talks about manipulating a qubit state with a magnetic field. Can you think of another way to bring a qubit to a higher energy level?