Input and Output with a Quantum Computer etc

[jaketodd]

What physical processes input information into and extract information out of a quantum computer? What I really want to know is: How do you get a qubit or quantum dot to take on a particular state and cause its' entangled partner to choose a state?

Thank you!

 

[f95toli]

It depends on the system. In general you need a "knob" that you can use to move the state of the system around on the Bloch sphere.
In most systems this is done using resonant pulses of some sort, usually (in e.g. NMR and solid state computing) this means applying short microwave pulses to the system.