kiutra: Shaping the Future of Cooling Quantum Computers

Quantum computers are cool – not just because they offer a fundamentally new paradigm for computing but also because, quite literally, many of them require cooling down to extremely low temperatures to function.

Even minor disturbances, such as thermal noise induced by heat, can cause quantum computers to lose their quantum state and prevent them from leveraging quantum effects for computing. Cooling them close to absolute zero reduces the thermal energy of their components and slows down their interactions with the environment. However, this is energetically costly, and bulky dilution refrigerators introduce a lot of overhead.

Kiutra was founded in 2018 by Alexander Regnat, Jan Spallek, Tomek Schulz, and Christian Pfleiderer to develop efficient, easy-to-handle, cryogen-free cryostats that facilitate scientific research and accelerate the development of quantum computers. It has raised several funding rounds, with its latest Series A closing in the fall of 2021, led by Trumpf Venture and Verve Ventures, with existing investors High-Tech Gründerfonds (HTGF), APEX Ventures, and the Initiative for Industrial Innovators joining the round. 

Learn more about the future of cooling quantum computers from our interview with the co-founder and managing director, Alexander Regnat: 

Why Did You Start kiutra?

Our founding team has a common background in research. We were all low-temperature physicists at the TU Munich, meeting during our PhD studies and working a lot with cryogenic equipment.

If you need to cool to extremely low temperatures, close to absolute zero, it’s common nowadays to use dilution refrigerators that involve cooling media like liquid helium. But, they’re bulky and costly. So we looked into magnetic coolers and were impressed by their simplicity, speed, and suitability for developing smaller, more efficient, and more scalable cryostats, e.g., for novel quantum devices. 

We saw an opportunity opening up in the nascent quantum market, especially for testing, quality assurance, and even long-term operation of quantum devices. So we developed an initial prototype for continuous magnetic refrigeration, financially supported through grants from the State of Bavaria and the Federal Government of Germany, and ultimately decided to found kiutra as a spin-off to bring the technology to the market in 2018. 

How Do Magnetic Coolers Work?

When you bring some magnetic materials into a magnetic field, they get warm. When you switch off the magnetic field, they get cold. Technically, we’re using this magneto-caloric effect that makes these magnetic materials act as solid-state refrigerants to reach very low temperatures. 

It leverages the magnetic field dependence of the material’s entropy. On an atomistic level, a magnet is a collection of magnetic moments. Therefore, the material’s total entropy is composed of the entropy of these magnetic moments and of its lattice vibrations, where the latter are a measure of the temperature. The more the lattice vibrations, the higher the temperature. Now if you bring a magnet into a magnetic field, the spins align with the magnetic field direction. As they get ordered, the magnetic entropy is reduced. If we keep the total entropy constant (by carefully controlling the process), the lattice entropy must increase, and thus the material gets warm.

Vice versa, if you switch off the magnetic field, the magnet can relax. Its spins can choose random directions, and the magnetic entropy is increased. At the same time, the lattice entropy is lowered, meaning that the material becomes cold. By mechanically connecting the magnet to a quantum device, you can cool it to extremely low temperatures, which can be easily automated and operated even by laypeople.

Thereby, we avoid having to handle cryogenic gases, like liquid helium, which is quite cumbersome and also expensive. Typically, you would need helium-3, which is not present in nature, but produced in a nuclear decay process, which makes it rare and expensive, and poses a threat to the sovereignty of quantum technologies. Our magnetic coolers don’t require such expensive resources.

Currently, superconducting qubits, ion traps, and neutral atoms are frontrunners – probably in that order – and we’re trying to serve all these technologies with our coolers. Our cooling technology is agnostic and can also serve other purposes besides quantum computing, e.g., quantum sensing. As quantum technologies mature and get by with more relaxed cooling requirements, this will lead to better scalability.  

How Did You Evaluate Your Startup Idea?

We did several PoC projects, continuous market research, and wrote a business plan, which got checked by coaches, e.g., from UnternehmerTUM as well as the popular Munich business plan competition. We eventually founded the company in 2018 after closing our first deal with a paying customer,  which was a great validation of the commercial interest in our technology. 

Since then we have developed both products and services for customers in academia and industry, gathering feedback to develop the right offering. The timeline for quantum computing is hard to estimate, but the cool thing about our technology (pun intended) is that we don’t depend on any single quantum technology to succeed. We provide the picks and shovels for the gold miners, so we can get traction early on in the gold rush. And once one of our customers hits a vein of gold, we’ll scale with them to become the leading player for testing, quality assurance, and long-term operations for cooling quantum technologies. 

What Advice Would You Give Fellow Deep Tech Founders?

Every day it becomes more evident that building a great company is all about the team, not just great technology. Take enough time to find, motivate, develop, and retain the right talent. It becomes more difficult the larger your team grows, as you have less personal contact. But a functioning team and establishing a very good company culture are crucial. Often people have issues not related to the company, but you can make a big difference by still listening to their issues and finding a solution together. Just over a year ago, we also hired a people and culture manager, and it’s been a great decision.