Quantum switches thrive in extreme cold

Most computers will need more than useful qubits – they will need an efficient way to control and read them without burdening the refrigerator with wires. This study shows that a commercial microelectromechanical device can work reliably at cryogenic temperatures and can help solve that problem. The device not only maintained a stable conversion below 10 K, but also exhibited low operating power, low resistance, and strong radio frequency performance. By developing a unique gate-pulse waveform, the researchers also suppressed cryogenic bursts and achieved stable operation over 100 million cycles, pointing the way to real devices for scalable quantum communications.

Superconducting quantum computing is considered one of the most promising platforms for next-generation computing, but transferring it to practical applications remains difficult. Today’s architecture relies on multiple cables connecting room-temperature electronics and processors that sit close to zero, creating strong surface and cooling barriers in liquid-cooled refrigerators. Cryogenic multiplexers have been proposed as a solution, however existing switching methods often face tradeoffs with loss of input, isolation, performance, or long-term reliability under extreme cold. Because large scale applications will require efficient signal routing and durable performance, there is a strong need to investigate switch technologies that can perform well in cryogenic conditions.

Researchers from Purdue University and Menlo Microsystems reported (DOI: 10.1038/s41378-026-01178-4) these findings in Microsystems & Nanoengineering on February 28, 2026, in a study that explores a commercial one-dimensional MEMS device for deploying quantum computing applications. The team tested whether an existing RF MEMS device could meet the stringent voltage, temperature, and reliability requirements of cryogenic multiplexing, and found that its performance remained strong—and in some respects improved—at about 5.8 K.

The researchers combined quantitative simulations with cryogenic and RF voltage measurements to test the switch’s performance in extreme cold conditions. The simulations showed less deformation of the structure as the temperature dropped, helping to maintain stable deformation behavior. Tests have confirmed that the traction voltage is reduced by about 3.1% at cryogenic temperatures, while the resistance is reduced by about 15.3%, an improvement related to the reduction of phonon scattering in the metal. In RF tests, the insertion loss remained below 0.5 dB across the key 4-8 GHz qubit frequency range, and the isolation exceeded 35 dB, both suitable for transporting quantum signals. The team also discovered a major low-temperature challenge: severe shock caused by the quasi-vacuum conditions inside the package. In order to solve it, they created a two-gate wave structure that reduces the speed of the cantilever effect, suppresses oscillation and enables stable operation with a switching time of about 3.3 microseconds. With that waveform, the device ran more than 100 million cycles without visible damage. The team went on to demonstrate a stable way to conduct SP4T signals even with sensible NAND and NOR operation at cryogenic temperatures, showing that the switch can act as more than just a simple turn-off feature.

The authors conclude that commercial MEMS switches are a promising candidate for cryogenic multiplexers in many ancient systems because they combine near-zero fixed power consumption, strong RF characteristics, and reliable low-temperature operation. At the same time, they note that challenges still exist, especially dielectric charging and stiction at high switching frequencies, which will require additional equipment and design improvements for future control-multiplexing applications.

The effects extend beyond a single test of the device. If commercial MEMS switches can be combined with cryogenic multiplexers, they can reduce the complexity of the wiring between room-temperature electronics and quantum processors, easing one of the central engineering hurdles in multi-qubit systems. Their compatibility with low-power operation and selective signal conduction make them very attractive for next-generation quantum devices. With further improvements in speed and reliability, such switches may enable scalable quantum computing applications, transforming the design of communications from a bottleneck to a bridge.

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References

DOI

10.1038/s41378-026-01178-4

Original Source URL

https://doi.org/10.1038/s41378-026-01178-4

Financial information

This research was conducted with funding from the Asian Office of Aerospace Research and Development (AOARD) under award FA2386-21-1-4088.

About Microsystems & Nanoengineering

Microsystems & Nanoengineering is an international online-only journal, open to publishing basic research results and opinions on all aspects of Micro and Nano Electro Mechanical Systems from basic to applied research. This journal is published by Springer Nature in collaboration with the Aerospace Information Research Institute, Chinese Academy of Sciences, supported by the State Key Laboratory of Transducer Technology.