  A quantum internet connects remote quantum processors that need interact and
exchange quantum signals over a long distance through photonic channels.
However, these quantum nodes are usually composed of quantum systems with
emitted photons unsuitable for long-distance transmission. Therefore, quantum
wavelength conversion to telecom is crucial for long-distance quantum networks
based on optical fiber. Here we propose wavelength conversion devices for
single-photon polarization qubits using continuous variable quantum
teleportation, which can efficiently convert qubits between near-infrared
(780/795 nm suitable for interacting with atomic quantum nodes) and telecom
wavelength (1300-1500 nm suitable for long-distance transmission). The
teleportation uses entangled photon sources (i.e., non-degenerate two-mode
squeezed state) that can be generated by four-wave mixing in rubidium atomic
vapor cells, with a diamond configuration of atomic transitions. The entangled
fields can be emitted in two orthogonal polarizations with locked relative
phase, making them especially suitable for interfacing with single-photon
polarization qubits. Our work paves the way for the realization of
long-distance quantum networks.
