Google might be able to do useful quantum chemistry with 100 qubits and they already have 72

The goal of the Google Quantum AI lab is to build a quantum computer that can be used to solve real-world problems. Our strategy is to explore near-term applications using systems that are forward compatible to a large-scale universal error-corrected quantum computer. In order for a quantum processor to be able to run algorithms beyond the scope of classical simulations, it requires not only a large number of qubits. Crucially, the processor must also have low error rates on readout and logical operations, such as single and two-qubit gates.

Google wants to get qubits with 10-9 errors so that 1000 qubits will have about 0.1% errors.

Google is not revealing Bristlecone’s error-correction or speed yet but they expect good numbers and hopes to show quantum supremacy very soon.

There is an improved quantum chemistry algorithm which would be exact with 100 error corrected qubits but could work for approximate solutions using 100 pretty good qubits.

Google could achieve useful applications with

SOURCES -Google Research, google, John Martinis