TLE4HSQ

Superconducting qubits are currently among the leading quantum hardware platforms. In order to further extend the technological lead and establish superconducting qubits as a frontrunner in and after the NISQ era, it is necessary to achieve error rates that are significantly lower than before. To this end, a Thermal Laser Epitaxy (TLE) is being commissioned. This is a coating process that enables patterned layers of a wide variety of material combinations in a vacuum. This should make more powerful superconducting quantum electronics possible.

Goals and procedure

The overall goal of the project is to improve the quality of superconducting qubits by orders of magnitude. The use of a special shadow mask, which is characterized by its heat and acid resistance, allows superconducting qubits to be manufactured entirely in ultra-high vacuum, thus exploiting the advantages of TLE for the production of superconducting quantum electronics: In addition to uncomplicated material exchange, these are primarily the high substrate temperatures (>2000 °C), the possibility of using any gases at pressures down to the millibar range, and the simultaneous direct evaporation of up to five different metals. This allows to grow high precision alloys (e.g. complex compound superconductors), epitaxial barriers and alloy profiles of highest purity.

Innovation and prospects

When the reliable and scalable production of high-performance superconducting quantum hardware becomes apparent at the end of the project term, a company will be founded that has its own TLE facility. This should create a long-term and independent source of high-performance superconducting qubits and quantum processors "made in Germany", contributing to Germany's quantum technological sovereignty.

The project is funded by the German Federal Ministry of Education and Research within the framework of the Federal Government Quantum Technologies.

The equipment for thermal load epitaxy was developed and manufactured by the Max Planck Institute for Solid State Research.

The principle of thermal laser epitaxy is described here.
A Twitter post about the project launch can be found here.
The project is described on the page of the Federal Ministry of Education and Research here.