Kazan Federal University presents quantum sensing technology for quantum computing hardware
A team consisting of Ph.D. student Denis Uvin, research associate Mikhail Cherosov, engineer Maksim Kuznetsov, and research associate Dmitry Frolov, representing the Quantum Simulators Laboratory under the leadership of Ruslan Batulin, Associate Professor at the Department of General Physics, has developed an integrated vacuum sensor for the hardware platform of quantum computing (electrons and ions on a cryogenic substrate; instrumentation as well as a calibration methodology are also presented).
Over the past decade, quantum technologies have made impressive progress. Last year was proclaimed by the UN as the International Year of Quantum Science and Technology in honor of the 100th anniversary of quantum mechanics. In some areas, such as quantum sensors and quantum key distribution, technologies are moving from laboratory settings into the production sector.
Among the many platforms for quantum computing, electrons on the surface of cryogenic substrates are among the most challenging in terms of practical implementation. However, scalability to 107-108 qubits per square centimeter (achievable thanks to modern lithography and control technologies based on the technology describing the interaction of light, typically at microwave frequencies, and matter composed of superconducting circuit elements, i.e., circuit QED or cQED) and high quantum coherence (ensured by a cryogenic substrate at ultra-low temperatures) remain strong advantages of such systems.
"Classical setups for studying electrons on the surface of liquid helium necessarily include an electron source. A thermionic cathode based on a tungsten filament is often used for this purpose. It is placed in a sealed cryogenic cell, and the degree of vacuum and cleanliness of this cell directly determines the success and reproducibility of expensive experiments, for example, those using refrigerators or mixtures with costly isotopes such as helium-3," explains Denis Uvin. "Since the cell is assembled in air, it must be thoroughly cleaned and pumped down to high vacuum before an experiment. For this reason, monitoring the residual pressure in the cell with a vacuum sensor is critically important for experimental stability."
The key novelty of the proposed approach is the use of the same tungsten filament not only as an electron source, but also as the sensitive element for vacuum monitoring. An article describing the development was published in the journal Vacuum.
The vacuum sensor is highly specialized for a specific quantum system, and therefore it can be used in further development of quantum-computer hardware complexes based on electron systems on cryogenic substrates.
"The development has dual functionality and sequentially serves as both an electron source and a pressure monitor at intermediate stages," Ruslan Batulin emphasizes.
In the field of ultra-low-temperature physics, the use of sealed cells and a capillary condensation line is of primary importance for experiments with electrons and ions on cryogenic substrates.
The work was carried out within the framework of the Priority 2030 program.
More information:
Twofold application of a helical tungsten filament for the hardware of a platform of quantum computation: electrons and ions on a cryogenic substrate
www.sciencedirect.com/science/ … ii/S0042207X25008899
Provided by Kazan Federal University
