New modules shrink and improve controls on current quantum computers

Quantum computing could eventually solve problems that normal computers cannot, but increasing the amount of quantum processing units, or qubits, in the technology requires much costlier and larger control system. Xu et al. reported an open source method to make quantum computing processor controller development more extensible.

Instead of tackling the problem in the traditional way – with a few, large discrete components processing signals in a series of steps – the authors combined signals with multiple, smaller mixing modules. This strategy decreased the size, cost, and failure rate of these devices, and demonstrated superior or comparable performance to equivalent commercially available systems.

“Our project is supported by the U.S. Department of Energy, and a large number of tests have been carried out on conventional control systems, component by component, to understand the performance impact to the quantum system,” co-author Gang Huang said, “Using modular design methods, we integrated low-noise components on a small physical size and maintain the RF performance.”

The module works by integrating several electronics devices on a small printed circuit board, which allows the authors to manipulate qubits from the electronics base band frequency.

To validate their modular design, the authors used loopback and systems integration tests to ensure each component worked as expected. They performed randomized benchmarking and found the device exhibited low noise for both single and two qubits gate process.

The team plans to continue improving their quantum-computer controller.

“We will continue to optimize the physical size and cost of the module, and further integrate with the arbitrary waveform generator to improve the extensibility of the control system,” Huang said.

Source: “Radio frequency mixing modules for superconducting qubit room temperature control systems,” by Yilun Xu, Gang Huang, David I. Santiago, and Irfan Siddiqi, Review of Scientific Instruments (2021). The article can be accessed at https://doi.org/10.1063/5.0055906 .