Stijn de Graaf

Research Scientist at Google Quantum AI, San Francisco

I'm a research scientist at Google Quantum AI, where I work on physics-informed models of large-scale superconducting quantum processors.Superconducting circuits cooled to a hundredth of a degree above absolute zero.

I did my PhD at Yale with Rob Schoelkopf, where I developed erasure qubitsAn error whose location is known. Codes can fix about twice as many of these.: superconducting qubits built so that their dominant error can be detected as it happens.

erasure detection in a dual-rail qubit

t = 0.0 ms
(|10⟩ + |01⟩)/√2 cavity A cavity B ancilla

checks 0 · erasures detected 0
Figure 1. Most errors in a quantum computer leave no trace. In a dual-rail qubitOne microwave photon in one of two cavities. Which cavity is the 0 or 1. the dominant error, photon loss, moves the system out of its allowed states, so it can be detected without measuring the qubit itself. A code that knows where errors occurred can correct about twice as many of them. Decay probability per step uses a toy 1 ms photon lifetime.

Selected work

Talks and press

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