Austrian researchers have developed a new method of entangling photons, with which it is possible to combine three photons at once, to increase the efficiency of data transmission in a quantum system, and thereby approach effective quantum teleportation.
Future technologies such as quantum computers and quantum cryptography require experimental mastery of complex quantum systems. Scientists from the University of Vienna and the Austrian Academy of Sciences have reached new heights in this matter. They tried to use more complex quantum systems than two-dimensionally entangled qubits to increase information capacity with the same number of particles. The developed methods and technologies in the future may help in the teleportation of complex quantum systems. This work was published in the journal Nature Photonics.
Like bits in traditional computers, qubits are the smallest units of information in quantum systems. Big companies like Google and IBM are competing with research institutes around the world to create more and more entangled qubits and develop a functioning quantum computer. However, a group of researchers from the University of Vienna and the Austrian Academy of Sciences have chosen a different path to increase the information capacity in complex quantum systems. Their idea is simple: instead of increasing the number of particles used, the complexity of each system increases.
“The peculiarity of our experiment is that for the first time three photons are entangled in it, and not two, as usual,” explains Manuel Erhard, lead author of the study.
The concept of creating three-dimensional entanglement / Austrian Academy of Sciences.
To achieve this goal, Viennese physicists used quantum systems with more than two possible states: in this case, we are talking about the angular momentum of individual particles of light. These individual photons have a higher information capacity than qubits. But entangling these light particles turned out to be quite difficult at a conceptual level. The researchers overcame this difficulty with a groundbreaking idea - a computer algorithm that autonomously searches for a path to experimental implementation.
Using a computer algorithm, which the researchers named Melvin, they found an experimental setup to reproduce this type of entanglement. It was extremely difficult at first, but generally it worked. After some simplifications, physicists still faced serious technological hurdles. The team was able to solve the problem using unique laser technology and a specially designed multiport.
“The multiport is the heart of our experiment; it combines three photons so that they are entangled in three dimensions,”explains Erhard.
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The peculiar property of three-photon entanglement in three dimensions makes it possible to experimentally investigate new fundamental questions about behavior in quantum systems. In addition, the results of the work could have a serious impact on future technologies, such as quantum teleportation.
“I think the methods and technologies we have developed allow us to teleport most of the total quantum information of a single photon, which can be important for quantum communication networks,” explains researcher Anton Zeilinger.
Vladimir Guillen