Cryogenic nanoscale metrology of quantum circuits

Quantum computing holds the potential to highly impact our society and revolutionize scientific research, healthcare, finance, and beyond.

As the complexity of quantum circuits increases, advanced tools for nanoscale metrology of the sources of decoherence and energy loss will become vital for large scale fabrication, inspection, and optimization of quantum devices and microcircuits.

The main obstacle is that in contrast to classical computation, solid state quantum devices operate at sub-Kelvin temperatures at which the currently available microelectronics metrology and thermal imaging techniques are inoperable.

In our ERC AdG project, we have developed a groundbreaking technique that provides for the first time cryogenic thermal imaging down to mK temperatures, with four orders of magnitude improvement in thermal sensitivity over the state-of-the-art room-temperature methods.

Based on superconducting quantum interference device on the apex of a sharp tip (SOT), it allows nanoscale imaging of the minute heating and energy loss arising from electron scattering off single atomic defects, that can provide the crucial metrology of the decoherence sources in quantum devices.

Moreover, the SOT delivers simultaneous imaging of the electrical currents flowing in superconducting circuits, essential for inspection and optimization of superconducting qubits.This PoC project is aimed at adaptation of the SOT lab technology to industrial metrology applications, including development of reproducible industrially-compatible device fabrication methods, boosting their environmental durability, enhancing the SOT functionalities, and development of sustainable characterization methods.

We will develop IPR strategy, explore establishment of industrial partnerships, and promote integration of the SOT sensors into existing industrial workflows, to deliver a precise metrology solution to advance quantum computing development and enhance the competitiveness of the European industry.