[Colloquium] Willow and Quantum Computing Below the Surface Code Threshold

Julian Kelly, Google

Title: Willow and Quantum Computing Below the Surface Code Threshold

Abstract: Quantum error correction provides a path to reach practical quantum computing by combining multiple physical qubits into a logical qubit, where the logical error rate is suppressed exponentially as more qubits are added. However, this exponential suppression only occurs if the physical error rate is below a critical threshold. In this talk, I will describe our new quantum chip “Willow” which meets this challenge, and demonstrates exponential suppression of error with a factor of Λ = 2.14 as a logical qubit is scaled up over code distances. We also use our Willow chip to repeat the Random Circuit Sampling benchmark and find the time to classically reproduce this result would be 10²⁵ years.