Quantum Key Distribution and Translating Poetry. Repeaters are a critical juncture in all modern digital communications. Enhancing weakening signals traveling through fiber-optic cables keeps the world connected.
The challenge of signal weakening was met and overcome with the development of the repeater. The repeater is a device which copies the signal and retransmits it with increased energy to the next node along the network. Its development and propagation took off through the 1990s and into the new millennia.
Now, with quantum key distribution, the quantum physics answer to secure communications, those laser or LED repeaters will need replacing to provide “cleaner” fiber-optics. Impurities in the current internet repeaters have been handled with error-correction and more fidelity in the fiber-optics cables among other technical improvements.
However, the delicate state of quantum information encoded into quantum bits, qubits, demands a pristine cable to provide uninterrupted throughput. Data encoded in the qubits can be destroyed “in a nanosecond courtesy of an impurity in the fiber optic cable.” And that is just the start of the challenges to getting quantum bits through fiber-optic cables. None of this is stopping research.
“The lack of reliable quantum repeaters is the reason quantum cryptography technologies today are often geographically constrained—and why people even bother keeping track of the distances over which the most far-reaching quantum cryptography-secured communications occur.”
There’s ample promise to overcoming the challenge of quantum repeater design. Researchers in Osaka, Japan, and Toronto, Canada, are working feverishly and believe they have at least a part of the reliable quantum communication repeater solution.
However, their solution is only partially designed. The current status of the quantum repeater “establishes the workability of perhaps the most important link in the chain: the translation of the initial photon’s quantum state into an intermediary swarm of photons that then convey the original photon’s quantum state into a receiving photon’s quantum state.”
Though not a total solution, their design is a step in the right direction to getting quantum communication established in a scalable, repeatable fashion. Find more at the below references.