Meet Marcos Crichigno, a Senior Quantum Algorithm Scientist, based in our Washington, D.C office.
Tell us a little about your role and what you do at Phasecraft?
I am a Senior Quantum Algorithm Scientist. My main responsibility is to identify good target problems for quantum computers and develop the algorithms needed to solve them.
How long have you been with the company?
I've been at Phasecraft for a little over two years, since the opening of the DC office.
What’s a problem you’ve worked on here that wouldn’t have been possible a few years ago?
Definitely the quantum system simulations we've been carrying out. We're carrying out simulations of complex quantum systems across different hardware platforms at a scale that wasn't possible just a few years ago. It's beyond what you can do with exact classical methods, and we're reaching the frontier where the quantum device starts performing at least as well as the best approximate classical methods, which have been developed over decades of research. It feels like we're at this inflection point where quantum is finally catching up with classical computing, and that's exciting.
Why do you think it’s important to create algorithms that will bridge the gap between today’s quantum computers and future hardware?
Necessity is the mother of invention. The challenges you face when you have a device that's limited in what it can do really force you to go back to first principles and understand whether the approach you are taking is the most optimal. The improvements we often find, which can be quite significant, are not only useful now but will also carry over to the fault-tolerant age as well.
What’s harder than people expect about building quantum algorithms?
Nature gave us this strange gift, the ability to harness quantum phenomena to speed up computation exponentially. It is a strange gift, though; it comes with many conditions and caveats and does not apply to all computational problems but only to some strange subset which we do not yet understand how to characterize fully. Identifying these targets is the crucial challenge, but it is not mechanical work; it’s really creative and at the frontier of research.
For today's devices, the challenge is compounded by the fact that they're not yet large enough to be able to correct errors that occur during the computation, an essential ingredient in developing the quantum computers of the future. Understanding which problems admit significant quantum speedups, even in the absence of quantum error correction, is an even harder but exciting problem!
What do you think is the most important real-world challenge that quantum computing could solve?
Honestly, I think it remains to be seen. Quantum computing was originally designed to simulate quantum systems, a sort of virtual laboratory for the quantum world. Physical phenomena where strong quantum effects are important are something quantum computers are naturally suited to simulate. That includes understanding quantum properties of materials or molecules, for instance.
But the boundary between the phenomena that can be simulated classically and what truly requires a quantum computer is at the edge of current research. Although we strongly believe there is a hard barrier to what classical computers can do, the tentative location of this boundary is shifting all the time, as we continue to improve our understanding and our devices.
What will be the most world-changing application of quantum computing? I suspect we can’t fully conceive it yet, but I wouldn't be surprised if it surprises us all.
What’s something people might not expect about working at Phasecraft?
The leadership team is a group of world-renowned quantum computing scientists whose work many of us had been following long before the company existed, which makes it a very inspiring place to work. There is a strong scientific culture of free inquiry and rigour, stemming from this and underlying everything we do. That is probably evident from the outside.
One thing I particularly appreciate is the ability to achieve things that one could not achieve individually or in a smaller research group. I'm a theorist, for instance, but the large-scale quantum simulations we've carried out recently wouldn't have been possible without additional expertise in programming and noise mitigation, among other things. Working at Phasecraft is like being part of a superorganism, and that feels great.
On a personal level, everyone is genuinely interesting, and we get to know each other better at company retreats, which often lead to conversations on the future of science and our ambitious ideas, interspersed with music jams until late hours. This is maybe something people would not expect.
