Cryogenic parametric amplifiers using carbon nanotube-based devices

PI: Ares, Natalia

Department: Engineering Science

The technologies of quantum computing, radio astronomy, space communications, and particle physics all rely on extracting maximum information from inherently weak signals. This requires ensuring that every available data point contributes to a measurement. The first-stage amplifier plays a central role in this process, as its gain, noise, bandwidth, and power dissipation dominate the performance characteristics of the amplification process.

In the context of quantum computing, amplification of the readout signals is critical for qubit measurement, and the performance and physical dimensions of the first-stage amplifier are essential for scalability towards large-scale quantum computing. Significant efforts have been made to develop amplifiers with minimum noise while providing high gain, particularly in the realm of superconducting qubits. However, newer qubit platforms such as spin qubits and hybrid qubits require an external magnetic field for their operation, making it impossible to use superconducting amplifiers.

We aim to use suspended carbon nanotube-based devices as electromechanical resonators for parametric amplification. These devices can have ultra-high quality factors of up to 5 million and exhibit parametric amplification, where amplification is achieved by varying a parameter of the system. Due to low loss in carbon nanotubes and compatibility with magnetic fields, such parametric amplifiers can provide a first-stage amplifier for technologies requiring magnetic fields without significantly increasing the overall footprint due to their nanoscale dimensions.

We will partner with Zurich Instruments, a trusted leader in signal-processing solutions for quantum technologies. Our project has the potential to benefit both big and small companies in the field of quantum computing, such as Intel, IBM, C12, and Quantum Motion, as well as other industries that require amplification of weak signals in the presence of magnetic fields.