Perhaps of interest as an aside: In trapped ion quantum systems the shared motional phonons ("sound quanta") are how 2-qubit gates are effected. If I remember

Perhaps of interest as an aside: In trapped ion quantum systems the shared motional phonons ("sound quanta") are how 2-qubit gates are effected. If I remember the steps correctly: 1) Cool a string of ions to their motional ground state in a shared harmonic potential (the ion trap) 2) Issue laser pulses to ion 1 to create an entangled state that couples the ion's internal excited state to 1 quanta of one of the shared motional phonon mode 3) Issue a similar laser pulse to ion 2, this one exciting it conditional on the presence of the motional phonon Now your two ions are entangled.