At Zero Point Cryogenics, we believe cryogenic innovation should be practical, accessible, and grounded in engineering excellence. Today, we’re proud to announce a major milestone: our Phase Separation Refrigerator (PSR) has been accepted and published as a US patent and published in the American Physical Society’s Physical Review Applied.
This system introduces the first new technology for continuous cooling below 1 K in more than 60 years. The PSR achieves steady-state temperatures down to 500 millikelvin without requiring large volumes of helium-3. Designed with performance, accessibility, and reliability in mind, the PSR opens new possibilities for researchers operating in a temperature range that has historically been challenging.
Rethinking Millikelvin Cooling
For decades, researchers aiming to reach millikelvin temperatures have navigated a narrow set of options. Helium-4 cryostats, such as our Continuous Cold 0.9 K Cryostat, are dependable and easy to operate but typically stop short at base temperatures around 0.9 K. Dilution refrigerators, while capable of reaching sub-10 millikelvin, demand complex heat exchangers and large helium-3 volumes that increase overhead cost. Helium-3 cryostats can reach around 0.3 K but have two major disadvantages. In one-shot operation, the cryostat can experience large temperature fluctuations due to the cycling processes. A continuous version would avoid these issues, but requires a substantial amount of helium-3, rendering the system impractical.
This left a gap for continuous cooling options between 10 mK and 1 K. Many low-temperature experiments and applications naturally reside within this temperature range, such as photonic quantum computing, quantum sensing, detector calibration, optical detectors, and low-noise materials research. Traditionally, researchers and industry would compromise between tradeoffs in complexity, cost, or reliability.
At Zero Point Cryogenics, we developed a way to change that.
Our research and development team, spearheaded by Dr. John P. Davis, CTO & Founder, developed a new platform tapping into this underserved market. By using the principles of helium phase separation and applying our practical experience in cryostat design, we created an entirely new system: the Phase Separation Refrigerator (PSR).
Our Lead Scientist, Dr. Paul H. Kim notes the following about the invention:
“Innovation is weird sometimes. While building one of our 0.9 K cryostats, we were thinking about the helium mixture typically used in a dilution refrigerator and convinced ourselves the mixture could be used for cooling at “warmer” temperatures. With some modifications and testing in our 0.9 K cryostat, we discovered that by creating phase separation, you can preferentially pump helium-3 and have comparable performance to a pure helium-3 system, but with a smaller volume of the costly helium-3.”
This patented system introduces a novel, continuous, evaporation-based cooling, exploiting the properties of a helium-3/helium-4 mixture at low temperatures to achieve sub-K temperatures without dilution refrigeration or large volumes of helium-3.
Simplifying Cryogenics, Without Compromising Performance
The PSR delivers high thermal performance with low operational complexity, making it an ideal solution for teams who need reliable access to millikelvin temperatures but want to avoid the limitations of existing technologies.
- Continuous operation, no cycling interruptions
- Base temperatures at or below 500 mK, ideal for long-duration experiments
- High cooling power, ~1 mW of cooling power at 600 mK, and more than 20 mW at 1 K.
- Integrated precooling, for fast cooldown and rapid sample turnaround
- Hands-free automation, for intuitive and precise control
This system’s novel evaporation-based cooling technique has now been formally patented and is only available from ZPC. Its real-world deployments prove that what was once theoretical can now be routine: accessible, reliable, and scalable cryogenics at millikelvin temperatures.
Dr. John P. Davis, CTO and Co-Founder of Zero Point Cryogenics notes the following about the invention:
“From day one, our goal has been to simplify the experience of operating at millikelvin temperatures. The Phase Separation Refrigerator is a direct result of that vision—a system that delivers continuous 500 mK temperatures without the complexity of dilution refrigeration. It’s incredibly rewarding to see this design move from idea, to experiment, to patent, and now into customer hands.”
Meeting the Rising Demand for Smarter Cryogenic Solutions
As more industries adopt cryogenics, from quantum computing to sensor calibration and low-noise physics, the demand for reliable, continuous, and cost-effective millikelvin platforms continues to grow.
The PSR meets that demand with a flexible form factor, an intuitive control system, and high reliability. It eliminates the complexity of dilution refrigeration and the burden of large helium-3 volume, offering research teams a powerful new option to grow their capabilities with confidence and efficiency. For teams looking to modernize or expand their cryogenic capacity, it offers a clear and compelling alternative.
Explore the Science Behind the Patent
Our approach to phase-separated continuous evaporation is now detailed in a peer-reviewed research article, authored by members of the ZPC team and published in Physical Review Applied. The paper outlines the technical innovations and results that led to the patent’s award.
Read the full article in Physical Review Applied here.
For a less technical, conversational approach to understanding how it works, you can read our blog post here.
Looking Ahead
With the patent now secured, Zero Point Cryogenics is actively engaging partners interested in deploying this system in new environments, from university labs and quantum startups to government agencies exploring low-temperature technologies. Our first PSR systems will be deployed as early as Spring 2026!
This patent represents more than a technical achievement. It’s a reflection of our team’s vision to create cryogenic tools that are reliable, intuitive, and built to accelerate innovation.
We’re excited to continue refining this platform, scaling it to new form factors, and working with collaborators who share our passion for pushing scientific boundaries—colder, longer.
Zero Point Cryogenics – Colder for Longer
Zero Point Cryogenics is an Edmonton-based company that manufactures high-end cryogenic equipment. The company is focused on designing robust and reliable dilution refrigerators and cryostats for our customers that will satisfy their space, size, and operational requirements. By creating the world’s most reliable dilution refrigerator, ZPC customers can focus on developing their quantum technologies instead of operating their refrigerators.
Contact our dedicated experts to discuss your cryogenic needs and visit our website to learn more at www.zpcryo.com.