Author Archives: Mateus Araújo

Writing off APS

My review about semidefinite programming was accepted by Reviews of Modern Physics. Great! After acceptance, nothing happens for three months. Then, the tragedy: we get the proofs. Now I understand what took them so long. It takes time to thoroughly … Continue reading

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Sharing the refereeing burden

I’ve just finished writing yet another referee report. It’s not fun. It’s duty. Which got me wondering: am I doing my part, or am I a parasite? I get much more referee requests than I have the time to do, … Continue reading

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A superposition is not a valid reference frame

I’ve just been to the amazing Quantum Redemption conference in Sweden, organized by my friend Armin Tavakoli. I had a great time, attended plenty of interesting talks, and had plenty of productive discussions outside the talks as well. I’m not … Continue reading

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First Valladolid paper is out!

A couple of days ago I finally released the first Julia project I had alluded to, a technique to compute key rates in QKD using proper conic methods. The paper is out, and the github repository is now public. It’s … Continue reading

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I got a Ramón y Cajal!

I’m quite happy, this is pretty much the best grant available in Spain, it gives me a lot of money for 5 years, including a PhD student and a postdoc. But the reason I’m posting about it here is to … Continue reading

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MATLAB is dead, long live Julia!

Since I’ve first used MATLAB I have dreamt of finding a replacement for it. Not only it is expensive, proprietary software, but also a terrible programming language. Don’t get me wrong, I’m sure it was amazing when it was invented, … Continue reading

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The smallest uninteresting number is 198

A well-known joke/theorem is that all natural numbers are interesting. The proof goes as follows: assume that there exists a non-empty set of uninteresting natural numbers. Then this set has a smallest element. But that makes it interesting, so we … Continue reading

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SDPs with complex numbers

For mysterious reasons, some time ago I found myself reading SeDuMi’s manual. To my surprise, it claimed to support SDPs with complex numbers. More specifically, it could handle positive semidefiniteness constraints on complex Hermitian matrices, instead of only real symmetric … Continue reading

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SDPs are not cheat codes

I usually say the opposite to my students: that SDPs are the cheat codes of quantum information. That if you can formulate your problem as an SDP you’re in heaven: there will be an efficient algorithm for finding numerical solutions, … Continue reading

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Redefining classicality

I’m in a terrible mood. Maybe it’s just the relentless blackness of Austrian winter, but I do have rational reasons to be annoyed. First is the firehose of nonsense coming from the wormhole-in-a-quantum-computer people, that I wrote about in my … Continue reading

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