Metrology for superconducting qubits

The EU’s Quantum Flagship aims to expand European scientific leadership and excellence in the quantum field. In this area, the development of quantum computers has drawn the greatest interest. These use ‘qubits’ that are analogous to ‘bits’ in classical computers but can exist as both “1” and “0” at the same time – and hold the promise of solving computational problems far beyond current classical computers. However, interaction of qubits with measurement equipment and the environment can ‘break’ this ‘superposition’ and destroy the qubit – a term called ‘decoherence’. Currently, decoherence has limited the number of qubits available for practical quantum computers and, so far, no superconducting qubit metrology exists worldwide. In addition, there are discrepancies on how qubit metrics are reported in the literature and by companies, which makes comparison of parameters and performance difficult.

Building on the work of SuperQuant, this project will provide an understanding of the decoherence mechanisms that limit scalability of superconducting quantum computers. New characterisation methods for qubit materials will be developed along with the peripheral devices used in quantum computing, such as amplifiers, and instruments for qubit control and read-out. The first Europe-wide Round Robin on basic parameters of single qubits will be performed and recommendations on single qubit production will be published in a best practice guide. The consortium will also investigate establishing new measurement services for qubit metrology.

This will further underpin development of quantum metrology and aid the Quantum Flagship in its aims of putting Europe at the forefront of this emerging industry.