New Methods and Technologies Could Eventually Allow for the Teleportation of Complex Quantum Systems
Future technologies, such as quantum computers and quantum encryption, will require the experimental mastery of complex quantum systems. Thus, scientists from the University of Vienna and the Austrian Academy of Sciences have begun to use more complex quantum systems than two-dimensionally entangled qubits. In doing so, they can now increase the information capacity using the same number of particles.
These new methods and technologies could eventually allow for the teleportation of complex quantum systems.
Much like bits in traditional computers, qubits are the smallest unit of information in quantum systems. Conglomerates such as Google and IBM are competing with research institutes around the globe to come up with a larger number of entangled qubits, to develop a functioning quantum computer.
However, a research group at the University of Vienna and the Austrian Academy of Sciences is pursuing a new way of increasing the information capacity of complex quantum systems.
Their idea is simple: Rather than merely increasing the number of particles involved, the complexity of each system is increased.
Manuel Erhard, the first author of the study, explained that the unique thing about their experiment is that for the first time, it entangles three photons beyond the conventional two-dimensional nature.
For this purpose, the Viennese physicists employed quantum systems with more than two possible states—in this particular situation, the angular momentum of individual light particles.
Now, these individual photons have a higher information capacity than qubits. But, the entanglement of these light particles turned out to be tricky on a conceptual level. The researchers surpassed this issue with an innovative, new idea: a computer algorithm that autonomously searches for experimental implementation.
With the help of a computer algorithm dubbed Melvin, the researchers discovered an experimental setup to generate this kind of entanglement. At first, this was very complicated. However, it worked in principle. After some simplifications, the physicists still had to overcome significant technological hurdles. They were able to solve these problems with state-of-the-art laser technology and a specially developed multi-port.
Manuel Erhard stated that this multi-port is the heart of their experiment, and mixes the three photons so that they are entangled in three dimensions.
The unusual property of the three-photon entanglement in three dimensions enables the experimental examination of new fundamental questions about the behaviour of quantum systems. Moreover, the results of this work could also have a major effect on future technologies, like quantum teleportation.
Anton Zeilinger said he believes the methods and technologies that they developed in this research enables them to teleport a higher proportion of the total quantum information of a single photon, which could be important for quantum communication networks.
The results of their work were recently published in the renowned journal Nature Photonics, titled “Experimental Greenberger-Horne-Zeilinger entanglement beyond qubits.”