This chapter covers:
- Implement a quantum program to move data around a quantum computer using classical and quantum control
- Recognize a new way of visualizing single qubit operations called the Bloch sphere
- Predict the output of two-qubit operations, and Pauli operations
Just as with classical computing, sometimes in a quantum computer you have some data here that you would very much appreciate being somewhere over there. Classically, this is an easy problem to solve by copying data around, but as we saw in Chapters 3 and 4, the No-Cloning Theorem means we in general can’t copy data stored in qubits.
Moving data classically
In some parts of classical computing, we run into the same problem of not being able to copy information for very different reasons. Copying data in a multi-threaded application can introduce subtle race conditions, while performance considerations can prompt us to reduce the amount that we copy data. The solution embraced by many classical languages (e.g.: C++11 and Rust) is to instead focus on moving data. Thinking in terms of moving data is helpful in quantum computing, though we’ll implement moves in a very different way.