Anthropic says Claude Mythos 5 autonomously optimized eight quantum-circuit primitives after receiving plain-language specifications and feedback from an automated evaluator. The system generated circuit designs for chemistry, optimization, quantum simulation, number theory, and numerical computing that Anthropic says used fewer qubits and gates than previously published designs. The work was led by Andi Gu through Anthropic’s STEM Fellows Program with collaborators including Harvard’s Susanne Yelin and Mikhail Lukin. In a 53-hour run, Claude developed a reversible modular-inversion method for elliptic-curve point addition. It derived a way to recover divsteps branch information from the numerical state rather than storing the full history. Anthropic says one resulting design uses 12% more qubits than the smallest earlier circuit while requiring 17 times fewer gates, expanding the available qubit-runtime trade-offs. Claude also redesigned the Reed–Solomon decoding step in decoded quantum interferometry, replacing an extended-Euclidean construction with Berlekamp–Massey decoding. A simulator tested 403 million sample decodings and found that reserving 19 qubits for one exceptional value was sufficient for nearly all runs; about one in 10,000 runs exceeded that capacity and failed within the allowed error rate. Anthropic says the decoder uses 12 times fewer gates than Google’s prior construction.

Kimi Delta Attention utilizes bra-ket notation for clarity in mathematical derivations, where column vectors represent states, row vectors represent duals, numbers represent scalars, and matrices represent linear transformations. In this notation, vectors are oriented to the right by default, while keys are oriented to the left within the linear attention structure.

A researcher claims that Microsoft's advancements in quantum computing are flawed due to fundamental Python errors in their methodology. Microsoft defends its findings, asserting that the research is valid and sound.

Google is developing a model to disclose the code-breaking capabilities of future quantum computers and propose mitigation strategies. The company has been at the forefront of transitioning to post-quantum cryptography since 2016.