An international team of researchers has developed a technology that has shattered a world record in continuous variable quantum teleportation. This latest technology offers a viable pathway enroute to high-performance quantum networks.

The study recently published in Nature Communications was conducted by experts from the Australian Research Council’s Centre of Excellence, Centre for Quantum Computation and Communication Technology’s (CQC2T), The Australian National University (ANU) node, in collaboration with researchers from A*STAR’s Institute of Materials Research and Engineering (IMRE), Singapore, Shanxi University, China, CQC2T’s University of Queensland node and the Joint Quantum Institute (JQI), United States.

Quantum technology promises to transform society, introducing a paradigm shift in how we comprehend performing computations and communicating with each another. Quantum teleportation is arguably one of the most intriguing manifestations of the technologies enabled by the nature of quantum mechanics. It plays a pivotal role in the development of many quantum technologies and is built upon quantum entanglement – conceivably the weirdest feature of quantum mechanics.

For teleportation to occur, two remote users share an entangled quantum state that serves as the communication channel. To be teleported an unknown quantum state is measured locally and subsequently reassembled at a remote location. In this way the quantum state is teleported from one user to another. However, in existing teleportation protocols it is not possible to teleport with perfect accuracy, due to limits on how much entanglement can be created in the lab. By introducing a probabilistic noiseless linear amplifier to the teleporter, the researchers were able to overcome this limit.

 “Our protocol overcomes the onerous constraints of existing quantum teleportation schemes, that is low fidelity and limited transmission distances. It improves the capability of the quantum teleporter in protecting fragile quantum states during long-distance transmission, making the system resilient to noise and loss.” Dr Sophie Zhao said.

As a PHD graduate from ANU, Dr Sophie Zhao spent over 3.5 years at Xanadu, a world-leading quantum computing start-up, and the Joint Quantum Institute, NIST, University of Maryland. Her most recent appointment of Program Manager, CQC2T ANU node works in the field of Quantum Repeater Technology.

Relying on a noiseless linear amplification scheme, the protocol revitalises the quantum information embedded in optical states of light. However, in the realm of quantum mechanics there is a price to pay for this improved performance – a finite success probability.

“Nevertheless, the protocol is heralded. When it works, the performance of the teleporter can be significantly enhanced, without demanding more entangled resources.” Dr Zhao said.

Co-author Dr Syed Assad is a senior Research Fellow at ANU and a scientist at A*STAR’s IMRE.

“By sacrificing the certainty of always teleporting successfully, we can improve the quality of the teleportation procedure. We can therefore tune the experimental parameters to obtain either a high probability of performing successful teleportation or to achieve high quality quantum teleportation.” Dr Assad said.

According to Lorcan Conlon, a scientist at A*STAR’s IMRE, one of the key strengths of this work is that it can be used to reduce the noise on certain quantum states. “In a future quantum internet, the quantum information that we are transmitting will become noisier as we send it over longer and longer distances. The fact that we can use our teleporter to reduce this noise can help to counteract this effect,” he said.