New data transfer efficiency record set

Computer technologists have set a new record for the transfer of information via superdense coding.

Sending quantum bits can potentially be twice as efficient as sending classical bits. But realizing this so-called superdense coding has been a major challenge. Brian Williams and colleagues from Oak Ridge National Laboratory, Tennessee, have sent quantum bits over a small fiber link, achieving a new record in bit density. Their technique utilizes the hyperentanglement of photon pairs—a combined entanglement in their polarization and time degrees of freedom.

The record-breaking transfer has been achieved at the U.S. Department of Energy's Oak Ridge National Laboratory. Superdense coding is a technique used to send two bits of classical information using only one qubit (a unit of quantum information). With the coding processes the types of particles used to process information include photons, protons and electrons.

In setting the record, the research group transferred 1.67 bits per qubit along a fiber optic cable. This broke the previous record of 1.63 per qubit.

The finding will help in the path towards developing quantum computing and finding cost-effective means to condense and transfer information very rapidly. In a research note, the lead scientist Brian Williams said that the “experiment demonstrates how quantum communication techniques can be integrated with conventional networking technology."