Russian Scientists Create Quantum Device Using Qutrits and Ququarts

Although quantum computers are typically described as devices built with qubits that can be in a superposition of two states at once, it is possible to go further and use qutrits which can be in a superposition of three states or even ququarts which is a simultaneous superposition of four states. Whereas a qubit is described mathematically as α|0> + β|1>, the qutrit can be described mathematically as α|0> +β|1> + γ|2>. Rigetti recently posted a Medium article showing how a qutrit can be implemented on their processors using their QUIL-T pulse control software. The Rigetti article pointed out that could be a potential way to significantly improve readout errors on their processors.

Now Russian scientists from the Russian Quantum Center and the P.N. Lebedev Physics Institute of the Russian Academy of Sciences are utilizing this capability to construct the equivalent of a four-qubit ion trap computer using only two physical ions. This is a step in their effort to provide cloud access to a universal quantum computer by the end of 2024. This is part of an effort funded by Rosatom, a Russian state corporation specializing in nuclear energy, nuclear non-energy goods and high-tech products, which is provided 6 billion rubles (about $80.6 Million USD) in 2021 and will provide an additional 23 billion rubles (about $309 million USD) through 2024 for research to create a quantum computer.

Additional information about this effort is available in a post (in Russian) available on the website of the Russian Quantum Center and also a new article posted on the website of Interfax, a Russian news agency.

January 3, 2022