  We propose a quantum repeater architecture that can operate under ambient
conditions. Our proposal builds on recent progress towards non-cryogenic
spin-photon interfaces based on nitrogen-vacancy centers, which have excellent
spin coherence times even at room temperature, and optomechanics, which allows
to avoid phonon-related decoherence and also allows the emitted photons to be
in the telecom band. We apply the photon number decomposition method to
quantify the fidelity and the efficiency of entanglement established between
two remote electron spins. We describe how the entanglement can be stored in
nuclear spins and extended to long distances via quasi-deterministic
entanglement swapping operations involving the electron and nuclear spins. We
furthermore propose schemes to achieve high-fidelity readout of the spin states
at room temperature using the spin-optomechanics interface. Our work shows that
long-distance quantum networks made of solid-state components that operate at
room temperature are within reach of current technological capabilities.
