Quantum computing is based on qubits, which contain the full information on the spinor which describes an electron. Essential ingredients require the ability to write and read such information. Here I consider mobile electrons, which move through mesoscopic quantum networks (made of quantum wires or of arrays of quantum dots). Combining spin-orbit interactions, whose strength can be tuned by external gate voltages, and the Aharonov-Bohm flux, which can be tuned by an external magnetic field, one can tune the properties of such networks, so that the outgoing electrons are polarized along a desired direction. This amounts to 'writing' the desired information on the spinor of the electrons. Given a beam of polarized electrons, the conductance of the same network depends on their polarization, allowing 'reading' the qubit information.
