Campbell McLauchlan

That's a wrap on the #Coogee25 Sydney Quantum Information Workshop! Thanks to all the brilliant speakers who came to talk about their research!

Now with a cool logo! #Coogee2025

@mattmcewen.bsky.social kicking of #Coogee25.

Slaughterhouse 5 was incredibly influential for me when I first read it. Still one of the only novels I've re-read. It's an amazing book!

A useless but awesome fact from reddit: the range of a trebuchet does not depend on the planet on which you fire it. E.g. on the moon, the initial launch speed is smaller but the gravity pulling the stone to the ground is weaker, and the effects cancel out. (from this blog post: shorturl.at/8AqV8)

This is really cool though!

Couldn't there be highly-energetic, stable, complex systems in a universe without significant energy dissipation? With slow energy dissipation there would be slow energy exchange between systems which could maybe lead to stability?

With this year's big successes in quantum error-correction, is a Nobel prize somewhere down the track? (Or maybe one for quantum computing more broadly?) If so, who would be on the list of possible recipients?

I hear rumours about Brisbane 2032...

You're thinking of "poll vultures" which are news outlets that, around election time, report constantly on the polls to maintain uninterrupted coverage

Campbell McLauchlan's review of Collapse 4/5: "...the Soviet Union fell victim to a perfect storm and a hapless captain." The main argument of this book is that the collapse of the enormous USSR was not inevitable and was helped along treme...

More thoughts here: www.goodreads.com/review/show/...

3.9bl in 1986 to 93.4bl in 1991.

Although I think it's hard to agree with everything in the book, it is a fascinating description of a tumultuous and very relevant period of history.

None of them really wanted to be heading up a coup.
- Interestingly, you can see continuity between the Russian nationalist reaction to Ukraine's declaration of independence and Putin's claims at the start of the invasion.
- A simple demo of reform failing: the number of rubles printed grew from

This is an incredibly well-researched account of how the Soviet Union fell apart. The main argument is that the collapse was not inevitable and it was helped along tremendously by Gorbachev's reforms.
Some interesting tidbits:
- The August 91 coup plotters were a nervous shambles from the start.

Can't wait for your reaction to tomorrow's connections! (love from Australia)

Additionally, while comparing the X3Z3 code numerically to the CSS Floquet code and two honeycomb code variants, we found some interesting features about the performance of those previously existing codes under biased noise models.

The bad (but interesting) news: you seemingly can't do as well as bias-tailored surface codes (or color codes). We relate this to symmetries and back this up with no-go theorems for Floquet codes suggesting the X3Z3 code might be optimal.

The good news: just as in the surface code, you find better thresholds and sub-threshold scaling using the X3Z3 code compared to other Floquet codes. You can also find bias-preserving measurement circuits.

Okay obligatory paper meme: Recently Setiawan, at Riverlane, and I released a preprint on how to tailor Floquet codes to noise that is biased towards, say, Z errors. This "X3Z3 Floquet code" could improve performance on architectures using, e.g. the heavy-hex lattice.
www.arxiv.org/abs/2411.04974

0 should always be at the top! Change my mind. Also while we're at it, world maps should be oriented South-up.

The Philosophize this podcast put me onto this essay. Love it! The podcast and the essay.

I'm loving Kant here: "Enlightenment is man's emergence from his self-imposed immaturity. Immaturity is the inability to use one’s understanding without guidance from another... Have courage to use your own understanding! That is the motto of enlightenment." From What is Enlightenment?

Would there be any observational consequences if the universe were in a mixed state rather than a pure state? This might be a question for the quantum reference frames crowd. But if not, then the distinction might just be metaphysical speculation.

Do cosmologists think in terms of maps on density matrices at all (Genuine question)? I thought it was all like scalar inflaton fields etc etc

Cool! Now do postdocs?.. 😁

I wrote a blog post on the Shor code for the non-expert back in the day! Not sure how successful I was at making it understandable, but it was fun to write. More QEC education in unis and elsewhere is a great thing!
universealacarte.blogspot.com/2020/08/code...