https://www.vice.com/en_us/article/vb5jxd/why-ibm-thinks-google-hasnt-achieved-quantum-supremacy

Google’s claim to “quantum supremacy” has finally been published in Nature, a month after its research was accidentally leaked online.

But quantum supremacy has definitely not been reached, according to IBM’s quantum computing research team, who argued in a blog post that it’s not even really a thing.