NITU MISIS and RCC: Digital twins for controlling quantum systems

The main articles are:

• Quantum computers and networks in Russia
• Quantum Computers and Quantum Communications

2024: Presentation of the control model for complex quantum systems

The University researchers MISIS Russian Quantum Center (RCC) and developed a model for controlling complex quantum systems, which they say opens up opportunities for faster transmission information and allows control over the dynamics of the system. This was announced on May 16, 2024 by TAdviser representatives of MISIS. According to the scientists, the proposed technique is useful for reducing the number of errors and suppressing noise in quantum devices. With its help, it will be possible to study various effects in the physics of many bodies, as well as look for new quantum materials. Modification of the model will allow observing systems at the macroscopic level, which, in turn, opens the way to controlling quantum systems between different phases of matter.

source = MISIS

According to MISIS, progress in quantum technologies has revealed many complex engineering, mathematical and computational problems. One is quantum optimal control - tuning control signals to achieve desired results in quantum systems. However, in quantum systems with a large number of particles, difficulties arise. This is because many-body quantum dynamics modeling requires large resources, growing along with an increase in the number of parameters or variables that can vary. This can be, for example, the position of the particle, its speed and other, so-called degrees of freedom. Optimization methods are used to adjust the control signal, requiring multiple simulations, which complicates the task.

And although it is difficult to solve the problems of managing many bodies in quantum systems, they can be solved at least partially, the university emphasized. Thus, scientists from NUST MISIS and RCC have developed simplified models - "digital twins" of quantum systems that effectively and accurately track the dynamics of subsystems.

"Finding optimal control for quantum systems is a task known for its complexity. We have developed a method for constructing 'digital twins' of quantum systems that make it much easier to look for effective effects. Our work is important for the development of quantum processors and quantum simulators, "said Alexey Fedorov, PhD, director of the Institute of Physics and Quantum Engineering NUST MISIS, head of the scientific group" Quantum Information Technologies "RCC.

source = MISIS

This method allows you to find optimal sequences of operations in such a way as to achieve the desired results, for example, to change the direction of local dynamics or transmit information. This allows you to automatically find effective control strategies in complex systems of interacting particles.

"We focus on using methods to prevent a state of thermal equilibrium with the environment, as this interferes with the implementation of quantum algorithms for computing and modeling. It is important for us to implement coherent control when fluctuations occur in concert and synchronously. In addition, we found generalized spin echo sequences for the system in the localized phase of many bodies, "一 said Maxim Gavreev, engineer of the laboratory of quantum information technologies at NITU MISIS.

As he added, the developed approach as a whole allows the study of interesting phenomena in quantum matter and can be useful for current experiments with noisy quantum devices of an intermediate scale.

Detailed results of the study are described in the journal Physical Review Research (Q1). The study was carried out with the support of grants from the Russian Scientific Foundation (project No. 19-71-10092) and the strategic project of NUST MISIS "Quantum Internet" under the program of the Ministry of Education and Science of Russia "Priority-2030" (project No. K1-2022-027).