Overview
- Google’s Nature paper says its Quantum Echoes algorithm on the Willow processor ran a physics task about 13,000 times faster than the best classical approach on a top supercomputer.
- The team executed the experiment on 65 of Willow’s 105 superconducting qubits with results that can be checked by other quantum devices or confirmed by laboratory measurements.
- Quantum Echoes implements an out‑of‑time‑ordered correlator via a forward‑evolve, single‑qubit perturbation and time‑reversal ‘echo’ sequence designed for experimental verification.
- A companion proof‑of‑principle study indicates the method can act as a molecular ‘ruler’ akin to advanced NMR, though practical chemistry and materials applications would require machines roughly 10,000 times larger.
- Experts welcomed the reproducible quantum speed‑up yet cautioned that fault‑tolerant systems remain distant, and current encryption schemes, including those securing cryptocurrencies, are not imminently at risk.