QCBRIEF
DARPA has awarded Qunnect a contract to harden its Carina entanglement distribution system against polarization drift, the fielded fiber bottleneck that degrades quantum signals on telecom cables.
The Defense Advanced Research Projects Agency has awarded Qunnect a contract to push the next generation of polarization-compensation hardware inside its Carina rack, the company said Wednesday in a release distributed via PRNewswire.
Photons carrying quantum states keep their polarization aligned only when the fiber they travel through stays still, dark, and temperature-stable. Real telecom fiber does none of those things: it heats up, vibrates, and gets rerouted. That environmental drift scrambles photon polarization and erodes the entanglement fidelity a quantum network needs to function. Qunnect's Qu-APC subsystem monitors the drift in real time and applies corrective adjustments, the company's release says.
Carina is currently deployed in four cities — New York, Bozeman (with Montana State University), Berlin (with Deutsche Telekom), and Albuquerque — running over installed telecom fiber rather than lab dark fiber, according to HPCwire and thequbitreport. Qunnect describes Carina as the "first commercially available turnkey quantum entanglement distribution system"; that framing is the company's own and not independently verified.
nextgov frames the award inside DARPA's broader push to scale reliable qubit transmission on the way to a viable quantum internet. Contract value, period of performance, and the specific DARPA program office are not in the public release.