a man and a woman wearing sunglasses with stars on them are standing next to each other on a pink background . ALT: a man and a woman wearing sunglasses with stars on them are standing next to each other on a pink background .

Our paper Agnostic Process Tomography (APT) has been published in PRX Quantum.

Check it out here: doi.org/10.1103/q2nb...

Thanks @laura-lewis.bsky.social, Elham and Mina for the fun collaboration!

This new technique turns out to be very powerful, also allowing us to recover the tight lower bound for mixedness testing using just a few elementary calculations!

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Screenshot of Lemma 4.3 from https://arxiv.org/abs/2507.06010

We prove our lower bounds using a new quantum analogue of the Ingster-Suslina method. Essentially, we find a convenient way to decompose the quantum χ^2 divergence between a mixture of states and a fixed reference state.

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Screenshot of the title and abstract of https://arxiv.org/abs/2507.06010.

New work with @booleananalysis.bsky.social! We prove instance-optimal bounds for quantum state certification when testers can measure all copies simultaneously, finding that the optimal copy complexity depends on how close to maximally mixed the hypothesis state is.

arxiv.org/abs/2507.06010

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