The gemstone spinel, traditionally valued for its vibrant colors similar to rubies and sapphires, has emerged as a promising material for storing quantum information. This breakthrough was achieved by researchers from Tohoku University, the University of Chicago, and Argonne National Laboratory, with their findings published in the journal Applied Physics Express.
Professor David Awschalom from the University of Chicago, who co-led the research, stated: “This discovery highlights the incredible potential of materials like spinel, which have long been prized for their aesthetic qualities but are now revealing profound scientific capabilities.” He further explained that utilizing spinel's unique properties advances understanding of qubit systems and expands tools available for quantum technologies.
Quantum information technology uses quantum mechanics to process and store information beyond classical systems' capabilities. Central to this technology are qubit systems. Solid host materials such as diamond or moissanite retain quantum information through atomic defects that trap electron spins. These gemstones' transparent properties help isolate qubits for stable manipulation.
Manato Kawahara from Tohoku University's Research Institute for Electrical Communication likened this to a snow globe: “The glass of the snow globe protects the objects from outside disturbances, yet we are still able to manipulate it when we shake it.” In qubits' case, magnetic or electric fields control their spin.
Previous research by these institutions in 2021 and 2022 laid groundwork for finding new solid-state spin qubit systems and streamlined discovery processes. This led researchers to test spinel using lasers to excite it and measure photoluminescence for analysis.
Spinel has shown two essential functions necessary for qubit operations: initialization and detection. Professor Awschalom noted future plans include manipulating and controlling the spin qubit for applications in sensing, communication, and computing.
The demonstration of a qubit function in spinel could open new opportunities in quantum technologies. The study is part of efforts by the Chicago-Tohoku Quantum Alliance formed in June 2023 between UChicago and Tohoku researchers to strengthen ties with Japanese companies and academia.
Citation: “Polarization-dependent photoluminescence of Ce-implanted MgO and MgAl2O4,” Kawahara et al., Applied Physics Express, July 19, 2024. DOI: 10.35848/1882-0786/ad59f4