Assembling Control Architecture for Integrated Quantum Circuits

Academic Institution: University of Glasgow

Academic Supervisor: Professor Martin Weides

Industry Partner: SeeQC UK Limited

PhD Student: João Barbosa

Start Date: 14th February 2020

Abstract

This project will address one of the main challenges for scalable quantum technology: how to multiplex large numbers of quantum circuits. The targeted breakthrough is the demonstration and manufacturing of a scalable architecture for control of superconducting quantum processors. Reliable, integrated circuits based on superconducting single-flux quantum (SFQ) digital logic capable of both control and readout will be designed, tested and then integrated with quantum circuits.

The fact that quantum circuits are typically operated in extreme conditions – millikelvin temperatures and single photon energies – means that conventional approaches such as the use of multi-layer CMOS circuits for time – or frequency multiplexing will not work.

SFQ technology offers a solution to this problem. This is a mature superconducting technology which has been used to manufacture reliable, reproducible, and highly complex circuits.

Our programme of research will transform the quantum circuit control electronics by integrating control and quantum chip as close as possible (minimising signal delay time) and using custom-made electronics for faster processing. The key is to maintain reproducibile high (or improved) coherence time, and fast, precise and reliable control gates. Both partners have conducted preliminary studies, including fabrication and testing of prototype control and quantum chips.