In a groundbreaking study published by Nature Communications, a team of international researchers from Wits University and ICFO – The Institute of Photonic Sciences has demonstrated the teleportation-like transport of “patterns” of light. This significant achievement marks the first-ever approach capable of transporting images across a network without physically sending the image, bringing us closer to the realization of a quantum network for high-dimensional entangled states.
The establishment of quantum communication over long distances plays a vital role in ensuring information security. While quantum communication with two-dimensional states, known as qubits, has been demonstrated between satellites over extensive distances, there is still room for improvement. Quantum optics offers the ability to increase the alphabet in communication and securely describe complex systems, such as unique fingerprints or faces, in a single transmission.
Traditionally, communicating parties physically transmit information from one to the other, even in the quantum realm. However, the recent achievement represents a paradigm shift by introducing the possibility of teleporting information without physical travel, akin to the teleportation technology portrayed in the iconic television series “Star Trek.” It is important to note that teleportation has only been demonstrated with three-dimensional states so far, necessitating additional entangled photons for higher dimensions.
The research team successfully conducted the first experimental demonstration of quantum transport using two entangled photons as quantum resources. By using a nonlinear optical detector that eliminates the need for additional photons, the researchers achieved a state-of-the-art 15 dimensions, with the potential for scalability to even higher dimensions. This breakthrough paves the way for quantum network connections with remarkable information capacity.
To illustrate the potential application of their findings, the researchers considered the scenario of a customer wanting to send sensitive information, such as a fingerprint, to a bank. In traditional quantum communication, the information must physically travel from the customer to the bank, leaving room for interception, even with security measures in place. With the proposed quantum transport scheme, the bank sends a single photon, one of an entangled pair, with no information. The customer then overlaps the photon with the information on a nonlinear detector, resulting in the information appearing at the bank as though it had been teleported. Crucially, no information is physically transmitted between the parties, rendering interception futile. The quantum link connecting the parties is established through the exchange of quantum entangled photons.
While the protocol presented in the study shares many characteristics with teleportation, the researchers identify one essential missing ingredient: a bright laser beam to enhance the efficiency of the nonlinear detector for the sender. Nonetheless, the experiment opens up a new pathway for connecting quantum networks and represents an important step forward for nonlinear quantum optics as a resource. The researchers hope that their findings will inspire further advancements in the field, ultimately leading to a full quantum implementation.
The researchers acknowledge the need for caution, as the current configuration cannot prevent a dishonest sender from keeping better copies of the information to be teleported, potentially causing multiple replicas of entities like Mr. Spock in the Star Trek world. Nevertheless, the demonstrated configuration can already establish a high-dimensional secure channel for quantum communication between two parties, provided that the protocol does not require single photon feeding, as would be necessary for quantum repeaters.
Moving forward, the research team plans to continue their efforts in advancing quantum communication. The next focus is on exploring quantum transport across an optical fiber network, a step that could bring us closer to realizing practical applications of this transformative technology.
As we celebrate the achievements of the research team, it is vital to acknowledge the contributions of Dr. Bereneice Sephton from Wits University. Her determination and comprehensive skill set played a crucial role in taming the experimental challenges and ensuring the success of this pioneering endeavor. The team also recognizes the heroic efforts of Dr. Sephton and expresses gratitude for her tireless work and key experiments that made this breakthrough possible.
The recent advancements in the teleportation-like transport of high-dimensional states brings us closer to establishing quantum networks capable of transmitting complex information securely. With the potential to revolutionize information security and communication, the possibilities for quantum communication continue to expand. As further progress is made, the foundations of a quantum future are solidifying, fostering a world where secure and instantaneous communication is within our grasp.