“This year saw the world’s first experiments demonstrating successful scaling of qubit systems with quantum error correction. This is a very important milestone for our field, since the implementation of universal quantum computers without an error correction system is impossible due to the extremely high sensitivity of quantum systems to noise,” said MIPT senior researcher Gleb Fedorov, whose words are quoted by the university’s press service.

He noted that it is of particular value that in 2023, for the first time on several platforms at once, physicists were able to experimentally demonstrate that increasing the number of physical qubits included in logical quantum bits actually improves the quality of operation and stability of these memory cells and elementary computing units quantum computer.

Another important “quantum” physical breakthrough of the year, as added by Alexey Kavokin, director of the Abrikosov International Center for Theoretical Physics (Moscow), was the creation by Austrian physicists of the world’s first quantum signal repeater based on calcium ions. According to him, this development has brought the world significantly closer to the creation of a worldwide network of quantum communications and to the development of distributed quantum computing systems, whose components are located at very large distances from each other.

About quantum error correction.

Many physicists now assume that further development of quantum computers will require the creation of systems capable of automatically finding and correcting random errors in their operation. Such failures inevitably arise in the operation of qubits, quantum memory cells and primitive computing units, as a result of their interaction with objects in the surrounding world.

Scientists have discovered that these random glitches in quantum computers can be suppressed by using so-called logical qubits, virtual quantum memory cells made up of several physical qubits connected to each other, for calculations. They are designed in such a way that errors in their operation are automatically corrected, which makes it possible to carry out complex and time-consuming calculations with their help.

In 2023, several scientific teams developed quantum processors based on a large number of logical qubits. Experiments with these computers demonstrated for the first time in practice that the use of logical qubits actually makes it possible to reduce the frequency of errors during long-term computer operation. One of the largest projects of this kind, a quantum computer based on 48 logical qubits, was created in the USA by the group of Mikhail Lukin, professor Harvard University.