ParityQC: Shaping the Future of Quantum Architecture

Scaling quantum computers isn’t just about adding more qubits—it’s about how you organize them.?

The architecture of a quantum computer determines how qubits handle processing, memory, and input/output, shaping the machine’s ability to solve complex problems and achieve real-world impact.?

ParityQC, founded in early 2020 by Wolfgang Lechner and Magdalena Hauser, is the world’s only company specializing in quantum architecture, creating blueprints and an operating system, ParityQC, for highly scalable quantum computers.?

From solving optimization problems on today’s NISQ devices to enabling general-purpose, error-corrected quantum computing, ParityQC is defining how scalable quantum computers are built and how quantum algorithms run most efficiently on these devices. Spun off from the University of Innsbruck and the Austrian Academy of Sciences, it has raised an undisclosed sum in spring 2024 from B&C Innovation Investments.

Learn more about the future of quantum architecture from our interview with the two co-founders and co-CEOs, Wolfgang Lechner and Magdalena Hauser:?

Why Did You Start ParityQC?

The founding story starts with an invention in quantum computing in 2015.?

Wolfgang Lechner, along with two colleagues at the University of Innsbruck, was researching how to process quantum information to unlock the full potential of quantum computers. The goal was to create an architecture that would allow quantum computers to solve commercially viable problems in the future—something existing ones haven’t achieved yet.

Central to our work was addressing the connectivity problem: the challenge of enabling qubits to exchange information efficiently within a quantum processor.?

Unlike classical computers, which rely on the von Neumann architecture where data can be freely copied, quantum computers face a unique constraint—you cannot copy quantum information due to the no-cloning theorem. This fundamental difference meant that quantum information needed to remain present and accessible at all times.

There are several solutions to address this issue. We started from scratch and came up with a fundamentally new way to represent quantum information: Instead of directly encoding information into the states of individual qubits, we expressed it in a relative way, which allowed us to devise entirely new quantum computers and algorithms.

We knew this was a groundbreaking invention, so we filed a patent and presented our work at conferences internationally. Shortly after, we got an acquisition offer from a major company that wanted to buy all the intellectual property. And if you get an acquisition offer that early, you know you got something valuable. So we decided not to sell, and instead, we founded ParityQC.?

How Do You Encode Quantum Information?

We started to develop the architecture of a quantum computer from scratch, inventing a new representation of quantum information.?

It’s not even about basic physics, i.e., how to implement a quantum computation on physical hardware, but it’s pure mathematics, i.e., a fundamentally new way to express quantum information and perform quantum computations. This makes it universal and compatible with any quantum computing hardware.

We don’t encode quantum information directly into individual qubits, but instead, we describe everything in relative terms using parity encoding. Parity is a general concept in mathematics and refers to whether a quantity is even or odd. For example, in a binary sequence, the parity of 1011 (three 1s) is odd, while the parity of 1100 (two 1s) is even.?

In our architecture, instead of storing the quantum state directly, we encode its parity—aggregated information about the quantum state—into the physical qubits of a quantum processor.

This comes with several advantages: Parity encoding can identify errors because changes to individual physical qubits, e.g., flipping a 0 to 1, alter the parity of the overall quantum state, so we can detect and correct errors more easily. Also, encoding multiple logical qubits into fewer physical qubits reduces the hardware requirements.

As an architecture company, we develop blueprints and an operating system for quantum computers that leverage parity encoding. We enable quantum hardware developers to build much simpler chips with significantly streamlined control, and we help them implement quantum algorithms much more efficiently by making them fully parallelizable.?

What Quantum Hardware Are You Work With?

Our ParityQC Architecture is hardware-agnostic, and we’re working with all major quantum hardware platforms, be it neutral atom, silicon spin, ion trap, or superconducting qubits. Every hardware platform has its own strengths and limitations, and our role is to invent the things that make these hardware platforms scale better.?

Take superconducting qubits, for example. A lot of research and development has gone into developing this platform, and big players like IBM or Google are betting on it. But superconducting qubits are like artificial atoms, requiring each qubit to be individually addressed and calibrated.?

This lack of a global control mechanism, combined with their relatively large physical size, poses challenges for scaling. Managing server farms with thousands of dilution refrigerators to house these qubits simply isn’t practical in the long term. A shift to smaller qubits, like spin or atom-based qubits, could alleviate these space constraints.

Neutral atom qubits have the advantage that all atoms are identical, so you can address all of them at once with one global laser. However, this comes with a trade-off as it gets more challenging to address individual qubits within the system.?

What prevents hardware developers right now from building a billion-qubit quantum computer is how you control the qubits. Printing qubits next to each other is pointless without a scalable control architecture. And this is where our ParityQC Architecture excels.

We allow quantum computers to be built using a single global laser drive for any quantum hardware platform and allow them to tackle any quantum problem. With this architecture, orders of magnitude more qubits can be controlled compared to current designs—all managed by one central control mechanism, a single laser.

Finally, the architecture is also independent of the mode a quantum computer will operate in. We have solutions for analog, near-term digital, and error-corrected quantum computers. Our strategy is to thrive at every stage as the quantum hardware matures.?

Where Do You Stand Today?

Our goal is to provide solutions for every stage and sell products at every stage. We’ve been generating revenue since early on, and we’ve been profitable since last year.?

It’s been great to be part of excellent consortia and collaborations. We’ve won several significant tenders, including one from the German Aerospace Center (DLR). We’re actively involved in key European and international research consortia, including the Hamburg Full Stack Quantum Machine Learning (HQML) project, which aims to develop a quantum solution for image data processing.?

Additionally, we’ve secured contracts for exciting projects, such as partnerships with eleQtron and NXP and a recent collaboration with Quantum Brilliance under the Cyberagentur initiative, which focuses on portable quantum computers. For us, the question isn’t whether we can build a quantum computer—it’s whether we can make it small enough to fit in a car.

We have shown that building a real, sustainable business is possible, even as a pure quantum company. Our team has grown to 60 people across multiple locations in different EU countries, all working on advancing our architecture.?

What’s The Opportunity for ParityQC?

As an architecture company, we have one straightforward goal: for hardware developers to build our architecture. We’re convincing them about the advantages of what we’re doing, and our dream goal would be to have ParityOS run inside every quantum computer.?

We’re on track to work with all major quantum hardware platforms, and over the next few years, we want to bring even more hardware developers to build our architecture in larger projects and consortia.?

We expect the quantum industry to develop in a way similar to the microprocessor industry. Silicon Valley became the hub of technological innovation we know today because of early investments in computers, starting with NASA Ames in the 1930s.?

NASA began purchasing computers to perform aerodynamic calculations for developing planes. For two decades, these computers offered no clear advantages over human calculators as the technology was too primitive to solve complex equations or replace wind tunnels.

However, NASA’s directors believed in the potential of computing and had to advocate for buying these machines despite their limitations. This early demand helped kickstart the computer industry, which ultimately laid the foundation for Silicon Valley. Today, there is no doubt that this early commitment to an emerging technology played a critical role in building the world’s largest and most successful tech economy.

This is a lesson Europe can apply to building its quantum computing industry. It’s why governments should buy quantum computers to kickstart the ecosystem and make Europe competitive as a region.?

Compared to the U.S., there’s always some doubt in Europe whether quantum computing is really this disruptive and whether we should invest now. There’s no longer any doubt in the U.S. that quantum will be a key technology. We don’t have tech giants in Europe who can push the development of quantum computers as Google or IBM can, so we have to fill that gap with government money.?

It’s generally encouraging to see Europe picking up pace. The region has always been famous for research, and many fundamental methods in quantum computing were developed here. However, commercialization has often happened elsewhere.

Germany led the way with a €2 billion stimulus package for quantum computing, while France and the UK have also pledged billions. It’s a promising sign that Europe is beginning to recognize its potential and even take the lead for some quantum technologies.??

What Advice Would You Give Fellow Deep Tech Founders?

Our motto is generally to be very selective about which advice we listen to. As a founder, no one else is in your shoes—only you have a complete understanding of your business, its context, and everything that’s happening. Be selective about the advice you follow, and remember that everyone offering guidance may have their own agenda. Trust your instincts and use advice as a tool, not a directive.