Large-scale magnetic cooling (LEMON) logo
Large-scale magnetic cooling (LEMON) logo

LEMON

Large-scale magnetic cooling

The focus of the LEMON project is to develop a scalable, helium-3-free cryogenic cooling solution capable of reaching milli-Kelvin temperatures. By pushing the limits of continuous Adiabatic Demagnetization Refrigeration (cADR), it will address the growing cooling demands in quantum technologies, particularly in quantum computing.

We will design and investigate a modular system that has the potential for large-scale refrigeration with high cooling capacities.

With our innovative approach, we want to eliminate the dependence on scarce helium-3 in cryogenic cooling.

LEMON is funded as part of an EIC Pathfinder Challenge. The project aligns with the goals of this challenge by providing a sustainable, energy-efficient solution, reducing environmental impact, and supporting the expanding field of quantum-based applications.

EIC Pathfinder Challenge

Clean and efficient cooling

Icons relating to EIC Pathfinder Challenge: Clean and efficient cooling

LEMON Objectives

Demonstrating the large-scale cooling capabilities of cADR

We will build a cADR demonstrator that will generate considerably lower temperatures than reached before, while simultaneously achieving significantly higher cooling power. To achieve this, based on preliminary work successfully carried out by us, key cADR components will be newly developed, tested, combined, and optimized individually, as well as in their interaction.

The proposed novel approach to large-scale cryogenic cooling offers the technical foundation for systems with, in principle, arbitrarily high cooling capacities by connecting the same basic cooling unit multiple times.

This project will enable the large-scale, industrial use of cADR technology. It will meet the growing and diverse cooling requirements of quantum technologies, particularly quantum computing (QC). The high cooling powers required for QC, ranging from several hundred µW to tens of mW, will be made available by means of magnetic cooling for the first time.

Insights into implementation and scaling

As a result of building and testing the demonstrator, the project will provide valuable insights into the implementation and scaling of the novel refrigeration concept. These findings will facilitate the replication of elementary cooling units, enabling future systems with even higher cooling power. Additionally, new scientific knowledge will be gained about a previously little-explored cooling process.

Concept art for Large-scale magnetic cooling

LEMON Impact

Paving the way for sustainable quantum cryogenics 

With this project we will show how significant capital and operating cost savings can be made for cryogenic cooling in quantum technologies. This will pave the way for a new quantum industry that will require extensive use of low temperatures for applications in quantum computing, quantum communications and quantum sensing. Successful implementation will address reliance on helium-3 for ultra-low temperature cooling – a critical resource challenge in the emerging quantum industries. Helium-3 is currently sourced from only a few North American and Russian suppliers.

It is one of the most poorly available resources for applied quantum technologies in Europe and has not been replaceable to date. Establishing a cooling method independent of helium-3 therefore promises supply independence, technological sovereignty, and a sustainable competitive advantage for the future application of quantum-enhanced high-performance computing. Finally, as part of the hardware and control software development of LEMON, the cooling system’s energy consumption will be lowered. This, in turn, will significantly reduce the greenhouse gas footprint in quantum cryogenics.

Project updates

February 2025

General news

A few months into the LEMON project, we are making big steps towards large-scale magnetic cooling. Within work package 1, our team is working on new designs to significantly increase the size (and thus the cooling capacity) of our refrigerant package and to improve the thermal conductivity performance of the mechanical heat switches. To this end, our testing cryostat, which will allow for rapid prototyping, is almost finished and will help us validate our theoretical calculations with experimental data. We have also started working on the overall system architecture, e.g. to also accommodate the new design for large ADR magnets.

Project information

Funded by the European Union

Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Innovation Council. Neither the European Union nor the granting authority can be held responsible for them. 

LEMON
Grant agreement ID: 101161522

DOI
10.3030/101161522

EC signature date
13 June 2024

Start date
1 September 2024

End date
31 August 2027

Funded under
The European Innovation Council (EIC)

Total cost
€ 3 968 750,00

EU contribution
€ 3 968 750,00

Coordinated by
kiutra GmbH
Germany

Do you want to push the limits?


    *required information.

    Contact us icons