I've spent this week celebrating the 100th birthday of quantum mechanics in the island of Helgoland, where Werner Heisenberg write his pioneering work. It's been so refreshing to see the impressive things that we can do, and all the exciting challenges that still lie ahead.

Seeing snow in May was definitely not in my year's plan... But it happened. Thanks to Isaac Smith and the rest of the organizing committee of the @uniinnsbruck.bsky.social DK-ALM Summer (?) School for inviting me to lecture on quantum information theory here at Obergurgl!

In order to figure out, we compared with (and improved upon) the distributions that can be created in the triangle network in any physical theory. And we see some regions of distributions that are very promising for observing this quantum advantage. We will focus on these in further work.

And here is the result. There are only two types of non locality in this scenario: the shared-random-bit (aka GHZ) type, and the all-but-one-parties-agree (aka W) type. The other part is an effect of relabeling the outcomes of the parties.

What does this tell us about quantum advantage?

So we parameterized all possible distributions achievable classically, and we looked for such form for all the distributions that are invariant under permutations of the parties (doing it in full generality would be too much)

In one meme for @dulwichquantum.bsky.social, this was (kind of) it

Some scientists care about observing phenomena in quantum networks that cannot reproduced in classical mechanics. One of the simplest scenarios is the triangle network with where all the parties perform a fixed, binary outcome measurement.

Is there any hope that we observe a quantum advantage here?

📢📢 New paper out! 📢📢

www.scirate.com/arxiv/2503.16654

We've computed all the tripartite probability distributions over binary events that 1) are invariant under permutation of parties, and 2) can be created in the triangle network within classical physics

Why should we care about this? Read on! 🧵

We give an explicit example for this, that we found when investigating quantum nonlocality in my beloved triangle network (heh).

In physics, we care about how and why things happen. We make models for this, which we capture in equations. For example, these are the Navier-Stokes equations, that describe the dynamics of fluids.

And, most importantly, if we tensorize one of these non-private models and we post-process the resulting TN using its gauge freedom, we obtain a model that works fine and does not leak unwanted attributes.

7/n

It seems like a tradition is emerging here, and it is out duty to maintain it. So here is my part announcing the publication of our review in semidefinite programming for characterizing quantum correlations @dulwichquantum.bsky.social

journals.aps.org/rmp/abstract...

Alrighty! I'm spending a few days at @ethzurich.bsky.social. Looking forward towards the discussions with @carrasqu.bsky.social and his group!