Why 99.9% Fidelity Isn't Good Enough | Arne Laucht, Diraq (Ep. 14)

Send us Fan Mail Blond & Quantum Episode 14: Why 99.9% fidelity isn't good enough — Diraq's silicon bet | Arne Laucht, Head of Technical Partnerships at Diraq A quantum computer that gets 999 operations right out of every thousand sounds excellent. Until it has to run a million of them in a row. Arne Laucht, Head of Technical Partnerships at Diraq and Associate Professor at UNSW Sydney, explains why that one error in a thousand is the whole story in quantum computing, and why Diraq is betting that the answer is the same silicon that sits in your phone. Diraq builds qubits from the spin of single electrons inside silicon, made on standard semiconductor production lines. Arne's case is simple: other approaches reach a million qubits by filling a warehouse with cryostats. Diraq wants to fit them on a single chip, in a single cryostat, running at about one kelvin. Arne's path runs from photonic crystal quantum optics in Munich, to a postdoc in Sydney fifteen years ago, to Andrew Dzurak's silicon group at UNSW, and into Diraq as one of its first people, where he led quantum measurement before moving to the US to run the company's technical partnerships. Listen to find out: 📍 What a silicon spin qubit is, and why the electron's spin beats its charge 📍 Why 99.9% fidelity still isn't enough when a real calculation needs millions of operations 📍 Physical vs. logical qubits, and why raw qubit counts are one of the most misleading numbers in quantum 📍 The three places quantum computing could matter (science, defense, commercial) and why cost decides which one you end up in 📍 Why running at one kelvin instead of millikelvin changes the economics of scaling 📍 What Diraq's 300 mm result with imec means, and why reproducibility beats a single record number 📍 What it took to make the case to DARPA's Quantum Benchmarking Initiative, and how Diraq sizes up Intel and HRL 📍 The one metric Arne wants investors to watch: price per computation Why it matters: silicon spin is the bet that quantum computing can ride the same manufacturing curve that made classical chips cheap. If it works, the winning machine won't be the one with the most qubits. It will be the one that can run a useful algorithm at a price a business is willing to pay. Guest: Arne Laucht is Head of Technical Partnerships at Diraq, the UNSW Sydney spin-out building silicon spin-qubit quantum processors on standard CMOS manufacturing lines, and an Associate Professor at UNSW. He did his PhD in physics in Munich, moved to Sydney as a postdoc, and was previously Diraq's Head of Quantum Measurement. Blond & Quantum is hosted by Eva Galant. Each episode features a leader from the quantum ecosystem — researchers, founders, and investors — for a laid-back conversation about how quantum technology is shaping the world without the equations. New episodes drop regularly. Subscribe wherever you get your podcasts. Watch on YouTube: https://youtu.be/So1QUree6i4 Support the show