  Quantum networks enable a broad range of practical and fundamental
applications spanning distributed quantum computing to sensing and metrology. A
cornerstone of such networks is an interface between telecom photons and
quantum memories. Here we demonstrate a novel approach based on cavity
optomechanics that utilizes the susceptibility of spin qubits to strain. We use
it to control electron spins of nitrogen-vacancy centers in diamond with
photons in the 1550nm telecommunications wavelength band. This method does not
involve qubit optical transitions and is insensitive to spectral diffusion.
Furthermore, our approach can be applied to solid-state qubits in a wide
variety of materials, expanding the toolbox for quantum information processing.
