In the race to build practical quantum computers, one of the most significant hurdles has been the complex wiring required to control the growing number of qubits. But a recent breakthrough from researchers at QuTech, Delft University of Technology, led by Job van Staveren, might just change the game. Their work, published in the IEEE Transactions on Quantum Engineering (translated as the IEEE Transactions on Quantum Engineering), introduces an integrated cryogenic solution for bias-voltage generation and distribution, a critical step towards scalable quantum computing.
The team developed a dedicated cryogenic CMOS (cryo-CMOS) demultiplexer and a cryo-CMOS DC digital-to-analog converter (DAC) using a 22-nm fin field-effect transistor (FinFET) process. This innovation is designed to control a 2-D array of 648 single-hole transistors, operating at temperatures below 70 millikelvin. “The key here is the tight integration of cryo-CMOS bias generation and distribution with a large-scale quantum device,” explains van Staveren. “This simplifies the wiring to the electronics, which is crucial for scaling up quantum processors.”
The implications for the energy sector are substantial. Quantum computers have the potential to revolutionize energy management, from optimizing power grids to accelerating the discovery of new materials for more efficient solar panels or batteries. However, these applications require quantum processors with a large number of qubits, something that has been challenging to achieve due to the complex wiring required to control them.
The system developed by van Staveren and his team addresses this issue by generating bias voltages at cryogenic temperatures and distributing them efficiently. The bias voltages generated by the cryo-CMOS DAC are demultiplexed to sample-and-hold structures, allowing for the storage of 96 unique bias voltages over a 3V range. The voltage drift is minimal, ranging from 60 microvolts per second to 18 millivolts per second.
This breakthrough could significantly simplify the control infrastructure for large-scale quantum processors, paving the way for more practical and scalable quantum computers. As van Staveren puts it, “This work is a step towards making quantum computers more practical and scalable, which could have profound impacts on various sectors, including energy.”
The research showcases the potential of cryo-CMOS technology in quantum computing, highlighting its role in simplifying the control infrastructure and facilitating the scaling up of quantum processors. As the field continues to evolve, such innovations will be crucial in realizing the full potential of quantum computing and its applications in the energy sector.