Quantum weaving is essential for next-generation information and communication technology, Aalto researchers can now produce it using temperature changes.
A joint team of scientists from Finland, Russia, China and the US have demonstrated that the temperature difference can be used to entangle electron pairs in superconducting structures. Experimental discovery, published in Nature Communications, promises powerful applications in quantum devices, bringing us one step closer to the applications of the second quantum revolution.
The team, led by Professor Pertti Hakonen from Aalto University, has shown that the thermoelectric effect provides a new method for producing entangled electrons in a new device. “Quantum intertwining is the foundation of new quantum technologies. “However, this concept has confused many physicists over the years, including Albert Einstein, who was very concerned about the thrilling interaction at a distance that it causes,” says Prof. Hakonen.
IN quantum computing, confusion is used to merge individual quantum systems into one, which exponentially increases their overall computational capacity. “Interlacing can also be used in quantum cryptography, enabling secure exchange of information over long distances,” explains Prof. Gordey Lesovik, from the Institute of Physics and Technology in Moscow, who has acted several times as a visiting professor at the Aalto University School of Science Given the importance of confusion in quantum technology, the ability to create confusion easily and controllably is a important goal for researchers.
The researchers created a device where a superconductor was layered graphene and metal electrodes. “Superconductivity is caused by tangled electron pairs called ‘Cooper pairs.’ Using a temperature change, we cause them to split, with each electron then moving to different normal metal electrodes,” explains doctoral candidate Nikita Kirsanov. , from Aalto University. “The resulting electrons remain entangled despite being split for quite long distances.”
Along with the practical implications, the work is of paramount importance. The experiment has shown that the Cooper couple separation process works as a mechanism for reversing the temperature change into electrical correlation signals in superconducting structures. The developed experimental scheme can also become a platform for original quantum thermodynamic experiments.
Reference: “Thermoelectric current in a Cooper graphene pair separator” by ZB Tan, A. Laitinen, NS Kirsanov, A. Galda, VM Vinokur, M. Haque, A. Savin, DS Golubev, GB Lesovik and PJ Hakonen, 8 January 2021 , Nature Communications.
DOI: 10.1038 / s41467-020-20476-7
The work was performed using the OtaNano research infrastructure. OtaNano offers the highest level of work environment and equipment for nanoscience and technology, and quantum technology research in Finland. OtaNano is operated by Aalto University and VTT and is available to academic and commercial users internationally. To learn more, visit their website. The work was supported by funding from the QTF (Academy of Finland CoE). Funding for the visiting professor by Gordey Lesovik came from the Aalto University School of Science and the Zhenbing Tan post-doctoral grant came from the Academy of Finland.