CMOS-based cryogenic control of silicon quantum circuits.

Area of Science:

• Quantum Computing
• Solid-State Physics
• Cryogenic Engineering

Background:

• Large-scale quantum computation requires millions of quantum bits (qubits), posing significant interconnect challenges.
• Current systems face a bottleneck connecting cryogenic quantum chips to room-temperature electronics.
• Complementary metal-oxide-semiconductor (CMOS) technology enables fabricating control electronics and qubits on silicon.

Purpose of the Study:

• To overcome the interconnect bottleneck in quantum computing.
• To demonstrate a cryogenic control chip for silicon quantum bits.
• To enable the development of fully integrated, scalable silicon-based quantum computers.

Main Methods:

• Fabricated a cryogenic CMOS control chip operating at 3 Kelvin.
• Utilized the chip to generate microwave bursts for controlling silicon quantum bits at 20 millikelvin.
• Benchmarked the control chip's electrical performance and fidelity.
• Coherently controlled qubits using the cryogenic chip and executed quantum algorithms.

Main Results:

• The cryogenic control chip demonstrated electrical performance consistent with 99.99% qubit operation fidelity.
• Achieved identical fidelity in controlling actual silicon quantum dot qubits compared to room-temperature commercial instruments.
• Successfully programmed and executed benchmarking protocols and the Deutsch-Josza algorithm on a two-qubit processor.

Conclusions:

• The cryogenic CMOS control chip effectively addresses the interconnect bottleneck in quantum computing.
• This technology enables high-fidelity coherent control of silicon quantum bits at cryogenic temperatures.
• The results represent a significant step towards realizing scalable, integrated silicon-based quantum computers.