Quantum networks: Back and forth are not equal distances

Quantum technology based on light (photons) has great potential for radically new information technology based on photonic circuits. Up to now, the photons in quantum photonic circuits have behaved in the same way whether they moved forward or backward in a photonic channel. This has limited the ability to control the photons and thus build complex circuits for photonic quantum computers. Now researchers from the Niels Bohr Institute have discovered a new type of photonic channels, where back an...