In many quantum technologies, two things work against each other: quantum entanglement and decoherence. Imagine they’re like opposing forces.
Quantum teleportation usually relies on perfectly connected pairs of particles (entangled qubits), but it’s easily messed up by decoherence, which disrupts those connections.
Researchers at the University of Turku, Finland, and the University of Science and Technology of China, Hefei, have proposed a unique solution to overcome this problem.
The novel method allows for high-quality teleportation to occur even in noisy environments.
“The work is based on an idea of distributing entanglement — before running the teleportation protocol — beyond the used qubits, i.e., exploiting the hybrid entanglement between different physical degrees of freedom”, said Jyrki Piilo, a professor at the University of Turku, in a statement.
The details of the team’s research were published in the journal Science Advances.
Harnessing noise for transmission
A quantum particle, or qubit, can be teleported by moving its state from one place to another without actually transmitting the particle. Quantum resources, like entanglement between an extra pair of qubits, are needed for this transmission.
In an ideal scenario, the qubit state can be perfectly transferred and teleported. However, the quality of teleportation is limited and diminished by the noise and disruptions that real-world systems are susceptible to.
Traditionally, photon polarization has been employed to entangle qubits in teleportation, but the present method takes advantage of the hybrid entanglement resulting from the combination of photon frequency and polarization.
“This allows for a significant change in how the noise influences the protocol, and as a matter of fact our discovery reverses the role of the noise from being harmful to being beneficial to teleportation”, said Piilo.
The teleportation protocol fails in the face of noise with typical qubit entanglement and in the scenario where hybrid entanglement and silence are present at first.
“However, when we have hybrid entanglement and add noise, the teleportation, and quantum state transfer occur in an almost perfect manner”, said Olli Siltanen, whose doctoral dissertation presented the theoretical part of the current research.
A milestone in quantum protocol
The team claims that the finding allows for nearly perfect teleportation even in the presence of specific kinds of noise when employing photons.
In their laboratory, the researchers have conducted numerous experiments exploring various aspects of quantum physics using photons. However, they highlight that witnessing the successful completion of this particularly challenging teleportation experiment was an immensely thrilling and rewarding experience for them.
“This is a significant proof-of-principle experiment in the context of one of the most important quantum protocols”, said Chuan-Feng Li, a professor at the University of Science and Technology of China, Hefei.
The uses of teleportation are significant, such as quantum information transfer, and it is critical to develop methods that shield this transmission from noise and enable more quantum uses.
The study’s discoveries offer fundamental insights with significant implications, paving the way for further exploration into extending the methodology to diverse noise sources and quantum protocols.
