Nov 5 2018
The experimental command over complex quantum systems is highly essential for future technologies such as quantum encryption and quantum computers. Researchers from the University of Vienna and the Austrian Academy of Sciences have been successful in crossing another huge hurdle.
The results of this work could also have a significant impact on future technologies, for example, the quantum teleportation (Image credit: unsplashLizenz).
Physicists across the globe have been attempting to raise the number of two-dimensional systems—the purported qubits; however, scientists working with Anton Zeilinger have been achieving new heights. They follow the concept to employ more complex quantum systems as qubits and thus can raise the information capacity using the same number of particles. In the future, the created technologies and methods could allow the teleportation of complex quantum systems. The outcomes of the study titled “Experimental Greenberger-Horne-Zeilinger Entanglement Beyond QuBits” have been recently published in Nature Photonics, a renowned journal.
Analogous to bits in traditional computers, in quantum systems, QuBits are the smallest unit of information. Major companies such as Google and IBM are competing with research institutes across the globe to produce an increasing number of entangled QuBits. The evident goal is to create a functioning quantum computer. However, a team of researchers from the University of Vienna and the Austrian Academy of Sciences is looking for an innovative way to raise the information capacity of complex quantum systems.
The concept behind it is straightforward: rather than just raising the number of particles involved, the complexity of each system is increased. “The special thing about our experiment is that for the first time it entangles three photons beyond the conventional two-dimensional nature,” explained Manuel Erhard, first author of the study. As a consequence, the Viennese physicists employ quantum systems having more than two possible states—in this specific case, the angular momentum of individual light particles. The information capacity of these individual photons is now higher than that of QuBits. Yet, on a conceptual level, it was found that the entanglement of these light particles was challenging. The team solved this difficulty using a pathbreaking concept: a computer algorithm with the ability to autonomously search for an experimental implementation.
An experimental framework for producing an entanglement of this type has been unraveled using the computer algorithm Melvin. Initially, it was found that this was still highly complicated; however, at least it worked in principle. Following certain simplifications, physicists were still faced with major technological difficulties. The researchers could overcome these challenges using sophisticated laser technology and a uniquely developed multi-port.
This multi-port is the heart of our experiment and combines the three photons so that they are entangled in three dimensions.
Manuel Erhard
The unique property of the three-photon entanglement in three dimensions enables experimental investigation of innovative fundamental questions related to the behavior of quantum systems. Moreover, the outcomes of this study could also have a considerable effect on future technologies like quantum teleportation. “I think the methods and technologies that we developed in this publication allow us to teleport a higher proportion of the total quantum information of a single photon, which could be important for quantum communication networks,” Anton Zeilinger points out into the future of possible applications.