Periodic Reporting for period 1 - LEMON (LARGE-SCALE MAGNETIC COOLING)
Berichtszeitraum: 2024-09-01 bis 2025-08-31
Quantum technologies – such as quantum computers, sensors, and secure communication systems – are expected to transform industry, science, and society over the coming decades. These systems require extremely low temperatures, close to absolute zero, to operate. At present, such cooling is provided almost exclusively by “dilution refrigerators,” which rely on helium-3, a rare isotope produced mainly as a by-product of nuclear weapons programs. Helium-3 is expensive, scarce, and controlled outside Europe, creating a major supply risk for the future quantum industry.
The LEMON project tackles this challenge by advancing continuous Adiabatic Demagnetization Refrigeration (cADR), a proven technology already commercialized by kiutra. Unlike dilution refrigerators, cADR does not rely on helium-3 but uses the magnetocaloric effect, where certain materials cool down when a magnetic field is removed.
What is new in LEMON is the step from today’s small-scale cADR systems to a large-scale version powerful enough to support quantum computers. The project’s objective is to demonstrate a system that delivers 20 microwatts of cooling power at 20 millikelvin – performance that matches the requirements of emerging quantum processors and goes far beyond current cADR capabilities. Achieving this milestone would open the door to even larger machines by replicating the same modular cooling units many times.
The project pathway to impact is clear:
- Scientific impact: establishing cADR as a credible alternative to helium-3 cooling.
- Industrial impact: laying the foundation for future quantum computing and related technologies in Europe.
- Strategic impact: reducing dependency on critical resources from outside the EU, supporting Europe’s technological sovereignty.
Given the projected multi-billion-euro global quantum market, the significance of this work is high. The ability to deliver scalable, helium-3-free cooling may become one of the essential enablers of the second quantum revolution.
The LEMON project tackles this challenge by advancing continuous Adiabatic Demagnetization Refrigeration (cADR), a proven technology already commercialized by kiutra. Unlike dilution refrigerators, cADR does not rely on helium-3 but uses the magnetocaloric effect, where certain materials cool down when a magnetic field is removed.
What is new in LEMON is the step from today’s small-scale cADR systems to a large-scale version powerful enough to support quantum computers. The project’s objective is to demonstrate a system that delivers 20 microwatts of cooling power at 20 millikelvin – performance that matches the requirements of emerging quantum processors and goes far beyond current cADR capabilities. Achieving this milestone would open the door to even larger machines by replicating the same modular cooling units many times.
The project pathway to impact is clear:
- Scientific impact: establishing cADR as a credible alternative to helium-3 cooling.
- Industrial impact: laying the foundation for future quantum computing and related technologies in Europe.
- Strategic impact: reducing dependency on critical resources from outside the EU, supporting Europe’s technological sovereignty.
Given the projected multi-billion-euro global quantum market, the significance of this work is high. The ability to deliver scalable, helium-3-free cooling may become one of the essential enablers of the second quantum revolution.
In the first year, the project concentrated on validating the most critical and high-risk components of the future cooling system. A dedicated cryogenic test platform was built, providing a test environment at very low millikelvin temperatures. This infrastructure now enables systematic studies and testing of the technologies required for large-scale continuous cooling.
Key achievements include:
- Establishing a versatile test system to support ongoing material and component evaluation at ultra-low temperatures.
- Advancing methods for preparing and handling refrigerant materials suitable for scalable milli-Kelvin cooling.
- Developing improved thermal switch concepts that promise higher performance than existing solutions.
- Demonstrating that modern manufacturing approaches can be applied successfully to components designed for cryogenic operation.
- Generating the first datasets that provide input for the detailed system design in the next phase.
Together, these results provide a solid foundation for scaling up towards the project’s demonstrator system.
Key achievements include:
- Establishing a versatile test system to support ongoing material and component evaluation at ultra-low temperatures.
- Advancing methods for preparing and handling refrigerant materials suitable for scalable milli-Kelvin cooling.
- Developing improved thermal switch concepts that promise higher performance than existing solutions.
- Demonstrating that modern manufacturing approaches can be applied successfully to components designed for cryogenic operation.
- Generating the first datasets that provide input for the detailed system design in the next phase.
Together, these results provide a solid foundation for scaling up towards the project’s demonstrator system.
Already in its first year, the LEMON project has advanced beyond the current state of the art in several areas of cryogenic technology. The work has shown that continuous magnetic cooling can be prepared for a new performance class suitable for demanding applications such as quantum computing.
Promising activities include:
- Exploring new ways to manufacture and optimize key components for operation at ultra-low temperatures.
- Advancing the design of thermal switches, which are essential for controlling heat flow in continuous cooling systems.
- Developing scalable methods for producing and integrating refrigerant materials.
These advances confirm that the pathway towards a helium-3-free, large-scale cooling solution is realistic. Looking ahead, further research, demonstration, and system integration will be essential to bring this technology from laboratory prototypes to industrial application. Support for innovation, intellectual property protection, and market uptake will be key for ensuring Europe can capitalize on this opportunity.
Promising activities include:
- Exploring new ways to manufacture and optimize key components for operation at ultra-low temperatures.
- Advancing the design of thermal switches, which are essential for controlling heat flow in continuous cooling systems.
- Developing scalable methods for producing and integrating refrigerant materials.
These advances confirm that the pathway towards a helium-3-free, large-scale cooling solution is realistic. Looking ahead, further research, demonstration, and system integration will be essential to bring this technology from laboratory prototypes to industrial application. Support for innovation, intellectual property protection, and market uptake will be key for ensuring Europe can capitalize on this opportunity.