Computational Complexity: My Quantum Summer
Rendering of PsiQuantum’s facility in Chicago |
I wasn’t looking for quantum this summer but it found me. At various events I ran into some of the most recognized names in quantum computing: Peter Shor, Charlie Bennett, Gilles Brassard and Scott Aaronson (twice), Harry Buhrman and Ronald de Wolf.
I was invited to Amsterdam for a goodbye event for Harry Buhrman. Harry co-founded and co-led the CWI quantum center QuSoft and has now moved to London to join Quantinuum as chief scientist and I was invited to give a talk on Harry’s classical complexity work before he joined the dark side. Ronald and Gilles gave talks after mine.
On the way to Amsterdam I spent a few days visiting Rahul Santhanam in Oxford. Scott Aaronson and Dana Moshkovitz showed up with kids in tow. Scott gave a talk on AI not quantum in Oxford. I would see Scott again at the Complexity conference in Michigan.
Peter Shor and Charlie Bennett both attended the Levin Event I mentioned last week.
I talked to all of them about the future of quantum computing. Even though I’m the quantum skeptic in the crowd, we don’t have that much disagreement. Everyone agreed we haven’t yet achieved practical applications of quantum computing and that the power of quantum computing is often overstated, especially in what it can achieve for general search and optimization problems. There is some disagreement on when we’ll get large scale quantum computers, say enough to factor large numbers. Scott and Harry would say growth will come quickly like we’ve seen in AI, others thought it would be more gradual. Meanwhile, machine learning continues to solve problems we were waiting for quantum machines to attack.
My city of Chicago had a big quantum announcement, the Illinois Quantum and Microelectronics Park built on an old steel works site on the Southeast Side of the city built with federal, state and local funds as well as a big investment from PsiQuantum. I have my doubts as to whether this will lead to a practical quantum machine but no doubt having all this investment in quantum will bring more money and talent to the area, and we’ll get a much better scientific and technological understanding of quantum.
PsiQuantum’s website claims they are “Building the world’s first useful quantum computer”. PsiQuantum is using photonic qubits, based on particles of light. Harry’s company Quantinuum is using trapped ions. IBM and Google are trying superconducting qubits. Microsoft is using topological qubits and Intel with Silicon qubits (naturally). Who will succeed? They all might. None of them? Time will tell, though it might be a lot of time.