Physicists have utilized the donut shape to achieve more reliable quantum teleportation. Think of it as a mini version of “Beam me up, Scotty.”
The method, described in the journal Nature Communications, allows them to use photons to transmit information without having to physically move it. They used high-dimensional states—which they dubbed “donut” states—for the teleportation.
In simple communication terms, the process of superdense-teleporting would work like this: one person encodes information in the form of a quantum state on his photon. Then that person performs measurement on his photon and then uses traditional communication channels (phone or email) to let the other person know what operation to perform on her photon in the laboratory to re-create the same quantum state.
“This process of a re-creation is essentially a transport without having any matter move from location A to location B,” says Tzu-Chieh Wei, an assistant professor in Yang Institute for Theoretical Physics at Stony Brook University. “Loosely speaking you could also view teleportation as a miniature version of teletransportation in the Star Trek movies.”
Shape of A Donut
Wei also likened the teleportation method as quantum information created and then stored in a kind of invisible parallel “shared folder” for end users.
A broadening and testing of this concept could help to form a quantum communications network that could potentially be used to encode and transmit useful quantities of quantum data for scientific experimentation and communication virtually anywhere on earth or in space.
The team took advantage of the mathematical properties intrinsic to the shape of a donut—or torus, in mathematical terms—to use “superdense teleportation.” The work, led by physicist Paul Kwiat of the University of Illinois, built on this new protocol for teleportation that was developed by co-author physicist Herbert Bernstein of Hampshire College in Amherst, Massachusetts.
The method effectively reduces the resources required to teleport quantum information, while at the same time improving the rate and reliability of the information transfer.
With this new method, the researchers experimentally achieved 88 percent transmission fidelity—twice that of 44 percent, the very best that could be achieved by any system that didn’t have access to the entangled quantum resource.
To make the whole process more efficient, the protocol uses pairs of photons that are “hyperentangled”—simultaneously entangled in more than one property, in this case in polarization and in orbital angular momentum—with a restricted number of possible states in each variable. Using multiple properties allows each photon to carry more information than the earlier quantum teleportation experiments.
The National Science Foundation and NASA supported the project.