Investing in Quantum Source: best in class team & technology

Omri Green
5 min readApr 19, 2023

The field of quantum computing (QC) has been of theoretical interest since the early 1980s. Its early promise was offset by challenging complexities that would take decades to overcome. While Isaac Chuang and team at IBM debuted the first two-bit quantum computer in 1998, it took until 2016 for a team at Google to show off a quantum computer that could best a classical computer at a specific problem.

That’s when things started to get interesting.

Governments worldwide began investing billions of dollars into quantum computing. Within a short time, the question was no longer whether a proof-of-concept is achievable, with an architecture that is based on a small number of qubits, but rather how to scale to a commercially useful quantum computer that will be based on a high number of qubits for computation. If scientific research can solve the complex scalability issue in quantum computing, the implications will be huge. Large-scale quantum computers are expected to instigate a revolution in entire industries thanks to their enormous, unprecedented computing power.

Even with these colossal government investments, full-scale commercial quantum computing is still several years away. There are many hurdles to realizing the full potential of QC tech but those obstacles are being overcome one by one by companies building the foundational “picks and shovels” that will propel them forward. Today, we announced our investment in one such company: Quantum Source.

I’ve been tracking this domain for investment potential since 2019 when I was investing at Grove Ventures (Is the Age of Quantum Computing Closer Than Imagined? & A Beginner’s Guide to QC), There, I led the first institutional investment in the Quantum Source team in 2021. I was very impressed with the team even at the earliest days. When I joined DTC, I expanded my search for teams innovating in the quantum space. I spent a year meeting teams in Australia, France, Canada, Israel, and the US looking for the best global team building the next compute system for our kids.

There are many amazing teams on the path to revolutionizing the quantum computing domain. Surprisingly (or not) I still think that Quantum Source is the right team to invest in right now. So, I am once again leading an investment round in the team.

Quantum Source’s Team (photographer: Ifat Golan)

Quantum Source’s amazing story, is unique in two aspects: the team and their very ambitious technology. Aiming to enable quantum computers to scale to millions of qubits, three serial entrepreneurs who sold companies to multinational corporations and one professor from the Weizmann Institute of Science joined forces to establish Quantum Source.

The Quantum Source Approach

So, why did we decide to partner with Quantum Source and its unique approach?

There are numerous approaches today to building quantum systems. The two most “proven out” approaches involve qubits based on superconducting circuits or trapped ions, both of which have successfully shown a small-scale system, but face several challenges in building a quantum computer that could be usable in the real world. Superconducting approaches require qubits to be held at extremely low temperatures, are expensive, and hard to scale up. On the other hand, photonics-based systems, although a relatively newer approach, have the promise to overcome these challenges and have a potential path to scale up to millions of qubits for two main reasons: a) Photons do not interact with the environment or with each other b) Photons can easily be generated in high volumes on a chip and time multiplexed using optical fibers.

Since 2016, photonics-based quantum systems have been seeing a large amount of research and investment. At this point, the field has progressed far enough that we have most of the “Lego blocks” that can be used as a foundation for building large-scale quantum systems. There is now evidence that it may be plausible to have a quantum computer using this approach in the next decade, and a lot of capable teams are working on this.

The first is the very promising and heavily-funded (more than $650M raised to date) PsiQuantum, which uses single photons as qubits. By the middle of this decade, the company promises to have completely set up all the manufacturing lines and processes necessary to begin assembling a final machine: a fault-tolerant, error-corrected quantum computer with hundreds of logical qubits and billions of gates.

“Rather than to try and scale a quantum process, we took a scalable process and have made it quantum,” said PsiQuantum’s CEO Jermey O’Brien in a video webinar. Back in 2009, he published a research paper that described how encoded photons of light could be used to perform quantum computations. Today, the company is promising to make this a reality: a general-purpose silicon photonic computer designed to facilitate quantum computing operations.

In May 2021, PsiQuantum and GlobalFoundries announced a breakthrough in their partnership to build the world’s first full-scale commercial quantum computer. The two companies are now manufacturing the silicon photonic and electronic chips that form the foundation of the Q1 system, the first system milestone in PsiQuantum’s roadmap, to a commercially viable quantum computer with one million qubits and beyond.

Another photonic-based quantum computing company that draws interest is Xanadu. With more than $250M in funding, the Toronto-based company’s platform leverages advanced artificial intelligence to integrate quantum silicon photonic chips into existing hardware to create a full-stack quantum computer. The latest news from Jan 2023 is the project they have with the Canadian government. Prime Minister Justin Trudeau announced a new federal investment of 40M CAD to enable Xanadu “to build and commercialize the world’s first photonic-based, fault-tolerant quantum computer.”

Quantum Source is solving a key piece of the puzzle for photonics-based quantum computers — efficient generation of photonic qubits and entangled states. The Quantum Source solution, based on single atoms trapped on a high-quality photonic integrated circuit, is capable of generating clusters of entangled photons five orders of magnitude more efficiently than existing photonic technologies. This means that a one million qubit system could be the size of a server rack. Look forward to the team sharing more details with the world on how they are able to accomplish these gains later this year and next.

Quantum Source silicon photonics chip assembly (Fraunhofer IZM)

The Quantum Source team is laser focused on execution, whether it be in research or engineering. I have seen the QS team execute since I invested in their seed. Their pace of progress and how they’ve hit their planned milestones has been remarkable to see. All of these factors together gave our team conviction that this is the right time for Dell Tech Capital to make our first and only bet so far in Quantum Computing.