How to produce a quantum computer, what are the most promising technologies to perform useful calculations with precision, what can be done now with these technologies? with Qandela' s' unit photon sources with rubidium atoms magnetically confined and cooled to 30 K by Pasqal Doppler laser with the spin of the NV centers of Diamfab with carbon nanotubes from C12 Quantum Electronics and Alice & Bob' s' error correcting technology.