  Internal states of polar molecules can be controlled by microwave-frequency
electric dipole transitions. If the applied microwave electric field has a
spatial gradient, these transitions also affect the motion of these dipolar
particles. This capability can be used to engineer phonon-mediated quantum
gates between e.g. trapped polar molecular ion qubits without laser
illumination and without the need for cooling near the motional ground state.
The result is a high-speed quantum processing toolbox for dipoles in thermal
motion that combines the precision microwave control of solid-state qubits with
the long coherence times of trapped ion qubits.
