Nicolai Friis

It's 2026. How are executions still a thing? Anywhere. But in particular, in supposedly modern and democratic countries? Executions are barbaric. Public executions are the tools of despots and dictators.

9 Sept

23 Aug

The Roll of Cthulhu 🐙🛼

Nicole Yunger Halpern@nicoleyh11.bsky.social

Ran into an evident escapee from a steampunk novel a few blocks from the National Book Festival #NatBookFest

kirwinhampshire.substack.comThe Dark Night of MathematicsWhat are we really doing?

2 Aug

This text has moved me deeply. I think we, as a species, have opened a door that we cannot close anymore. It will bring many advances, and some good will hopefully come from that, but we pay a price, the price of losing something profound. kirwinhampshire.substack.com/p/the-dark-n...

tuwien.atDon’t be afraid to try new things!Constantin Nistor is the first graduate of the Master programme Quantum Information Science and Technology.

29 July

Two years running, our Master's program in Quantum Information Science and Technology (QIST) at @tuwien.at has its first graduate: congratulations to Constantin Nistor and his advisor Daniel Platz! Looking forward to meeting the new/third student cohort this fall! www.tuwien.at/en/tu-wien/n...

One thing that I really have a hard time understanding is why it seems to be so difficult for researchers (at least in my field/experience) to get one of the most basic things in scientific writing correctly: references. So here is my (unsolicited) advice on how to sort out your references: (1/16)

Doi: Everything that is published online these days (and many things that have been published a while ago) is assigned a digital object identifier (doi), which means that the document can be found online on a permanent url doi.org. Best use that in the url = {} field. (15/16)

Preprint: It's not strictly necessary to add @arxiv.bsky.social information for published articles, and many publishers will remove it in published versions, but I think it is good practice to add arXiv numbers and remind people to put things on the arxiv to make research publicly available. (16/16)

Journal field: If your style file can switch between abbreviated and non-abbreviated titles, put the full title, otherwise pick one and be consistent. Make sure to use standard (iso4) abbreviations. (13/16)

Volume, Pages, Year: Make sure they are there. That's it. Page numbers these days are often not actual page but article numbers, but they still go in the pages = {...} field. Be careful of publishers using ascii hyphens for page ranges, your compiler will not like that. Use {\textendash}. (14/16)

I would also encourage using full first names in addition to last names. This gives more visibility to underrepresented groups and also makes it easier to distinguish authors with the same last name. Saving space on a printed page really is not a concern anymore today. (11/16)

Title: if there are capitalized words in the title (e.g., "Hilbert" or the title has every word capitalized as in the titles of PRLs), then these capitals will not be printed unless one wraps those letters or the entire title in exta {...}: use title = {{This is the Title of the Paper}} (12/16)

Also be careful with importing/copying bibtex entries from publisher websites, they often make basic mistakes. proper nouns in titles are not protected, DOIs and URLs are misidentified/exchanged, URLs lead to publisher websites, page numbers missing etc. So what to look out for? (9/16)

Authors: Use the format author = {Lastname, Firstname and Lastname, Firstname and … } so that bibtex can properly resolve multiple first or last names and suffixes correctly. Use tex commands for accents/special characters, utf8 input encoding may not work with some sty files. (10/16)

Now comes the advice that goes along with setting up a bib file: The most important thing first, and I am not sure who needs to hear this, but DO NOT LET LLMs TOUCH YOUR BIB FILE! Once the not so intelligent AI has gotten its grubby digital fingers on your carefully curated .bib file... (7/16)

...it will be filled with random imaginary author lists, fake journal references for preprints, fake preprint numbers, fake DOIs, and other fun AI hallucinations. Once this has happened, you will have no choice but to cross-check every single entry, line by line, name by name, digit by digit. (8/16)

Step 3: Set up a .bib database for bibtex. This will be the centre piece for your bibliography. I use one such file, I add entries by hand, if you check each entry once, you can be sure it is correct and continue to use and updated the same .bib file for every project. (5/16)

Step 4: Along with your template and .bib file, you want to chose/create/modify one or more style files for bibtex. Make sure the style files call the fields you use in the bib file, or vice versa, that your bib file contains the fields the style files call. (6/16)

Sure, you can use Overleaf. I use it a lot. But I have local copies of all my papers. It often happens that there is no internet connection, some DDOS attack, or other fun reasons why one cannot access Overleaf. You can of course simply hope this doesn't happen the day before a deadline. (3/16)

Step 2: Create working templates for the types of documents you usually handle, articles, theses, etc., make sure they compile on your machine. You can use those also whenever you do start a project on Overleaf. Almost anything will compile there, but not necessarily the other way around. (4/16)

Step 1: Use (La)TeX with Bibtex. On. Your. Computer. Yes, this means installing a Tex distribution on your machine. It is easy and free, find a decent distribution, like MikTex and a compiler, I like WinEdit, but use whatever you like/have access to. "I just use Overleaf", you will say. (2/16)

12 July

Yesterday someone called me out for only having joined Instagram to drop the occasional Pratchett quote without explanation. I mean, it isn't not true. But: It's not worth doing something unless someone, somewhere, would much rather you weren't doing it.

Bear with me, this will end on a high note. At times I feel that the workload and responsibility that comes along with supervision can be a lot, often because besides the actual work, academia as well as life outside of academia can be challenging emotionally, both for mentors and mentees. (1/8)

In the meantime, my student Tomasz Andrzejewski and Esprit Fellow Phila Rembold managed to put the finishing touches on a longstanding project and I am very happy to say that we just uploaded the resulting paper on creating genuine multipartite entanglement between logical qubits to the arXiv. (7/8)

So, if it seems like things are at times looking dreary for you as a mentor or mentee, supervisor or student, hang in there, believe in yourself and believe in your students, be patient, be kind, be understanding, everyone has bad stretches, but things will be looking up again! (8/8)

Then I had the pleasure to attend the 2026 Seefeld Quantum Information Workshop, where my student Ida Mishra enthusiastically presented a poster on her upcoming paper on high-dimensional entanglement and APART-MINT Fellow Simon Morelli advertised his work on sequential parameter estimation. (5/8)

This was followed by another brilliant PhD defense by Klára Baksová, who (unfortunately for me) will soon be leaving the group to start a postdoc in Prague, I am sure she will succeed there! (6/8)

So I consider it an imperative to be there for my students when there seems to be no light at the end of the tunnel. The flip side: It is then with even greater joy that one can witness the moments where one sees one’s students succeed, and recently I had this privilege on several occasions... (3/8)

On 17 June, my (by now I should say former) student Nicky Kai Hong Li defended his PhD with flying colours, and I am very happy that he will be staying on for a postdoc with a Croucher Fellowship! (4/8)

As a supervisor, one feels the pains and pressures of the talented people that one is trying guide through difficult patches, not least because more experienced academics in supervising positions have themselves experienced directly how tough, competitive, and sometimes cruel academia can be. (2/8)

19 June

Wait a second ... ISTA's lecture hall is called the "Raiffeisen Lecture Hall"? Since when is it good practice to name lecture halls at universities after sponsors? In particular, sponsors still in business w. countries starting wars of aggression, committing war crimes & political assassinations?

Institute of Science and Technology Austria (ISTA)@istaresearch.bsky.social

Register now for the ISTA Lecture by Ignacio Cirac to learn how quantum devices are pushing the boundaries of what’s computationally possible, and how near-term quantum computers can already serve as powerful tools for scientific discovery even in the presence of errors. 🔗 https://bit.ly/3RPhzXn

18 June

What a brilliant day, three consecutive defenses: It was an honor to serve on the PhD committee of Philipp Sohr (middle), and then very proud to see my student Nicky Kai Hong Li (second from right) defend valiantly, before leaning back as Marcus' (left) student Iraj (second from left) took the stage

QuOI Theory@quoi-theory.at

What's better than celebrating a PhD defence? How about THREE? Congrats to Drs (L-R) Umesh, Sohr, and Li for finishing their doctorates (and organising a three-in-a-row defence day!)

21 May

Me, when someone shows me a plot without axes labels

15 Apr

I am receiving invitations to predatory/fake conferences every day, but this one feels like a personal burn 😅🔥

23 Feb

10 years after its founding, driven by the energy, enthusiasm, & dedication of the community @quantum-journal.bsky.social quietly published paper #2000 some days ago. At least I think this is a big deal, big shout out to the founders & all authors, reviewers, editors, board members & contributors!

22 Feb

Some quantum info researchers are reluctant to learn about non-CPTP maps, but are ultimately left with no Chois.

29 Jan

QuOI is happening?

QuOI Theory@quoi-theory.at

Hey quantum Bluesky! Allow us to reintroduce ourselves! You may know us as QuIT: Marcus Huber's Quantum Information and Thermodynamics group at TU Wien. But we're so much more than that, and it's time our name reflected it. So say hello to... 𝗤𝘂𝗢𝗜? quoi-theory.at

19 Dec 2025

Over on LinkedIn the spirit of the season is spreading with a joyous round of pre-holiday bragging about publication metrics 🎄

quantum-journal.orgLUCI in the Surface Code with DropoutsDripto M. Debroy, Matt McEwen, Craig Gidney, Noah Shutty, and Adam Zalcman, Quantum 9, 1936 (2025). Recently, usage of detecting regions facilitated the discovery of new circuits for fault-tolerantly...

14 Dec 2025

Was an honor and pleasure to serve as handling editor for this paper, not just because it was a very nice piece of work, but also bc I enjoy good puns and pop- (or in that case, rock-)culture references (admittedly, also the bad ones), not sure if the authors noticed mine in the decision letter

Quantum Journal@quantum-journal.bsky.social

Published in Quantum: LUCI in the Surface Code with Dropouts by Dripto M. Debroy, Matt McEwen, Craig Gidney, Noah Shutty, and Adam Zalcman doi.org/10.22331/q-2...

27 Oct 2025

Social(-media) experiment: I posted the same blurb on our new research paper on Bluesky and on LinkedIn. Apparently many more people from the quantum bubble on LinkedIn (~5 times as many reactions), but actual responses there mostly nonsense and people trying to plug their business

Quantum networks might one day enable more secure options for communication and distributed computation and are therefore currently a hot research topic, one which presents many challenges: One is the on-demand distribution of quantum systems that feature genuine multipartite entanglement (GME). 1/8

doi.orgEntanglement of Trapped-Ion Qubits Separated by 230 MetersResearchers have achieved long-distance entanglement between two calcium ions, each of which lies in a different building, showing that trapped ions could be used to create quantum networks.

We confirm this by testing purpose-designed GME witnesses based on fidelities to 8 different GHZ-type states. In the future, the photons can be mapped onto remote matter-based qubits, e.g., as in doi.org/10.1103/Phys.... Besides being the 1st experimental verification of theoretical ideas ... 7/8

… the significance of our new work lies in presenting a clear path to efficiently distribute arbitrary GME states in future quantum networks. The 1st main challenge is overcome: GME states are precisely & reliably generated in a (trapped-ion) quantum processor & mapped onto traveling photons. 8/8

In their lab, they demonstrated the core functionalities of a factory node based on trapped ions by producing and verifying GHZ-type GME between three photons generated from the ions and sent to the end nodes, the latter for now represented by photon detectors in our setup. 5/8

Specifically, three ions are stimulated to each produce a photon (a), with which they are pairwise entangled (b). Then suitable quantum gates and measurements are applied to the ions (c) to remotely prepare GME states of the distributed photons (d). 6/8

A proposal for realizing a light-matter interface to generate GME is a central matter-based “factory node” that can be programmed to efficiently distribute arbitrary photonic GME states to surrounding clusters of network nodes. 3/8

arxiv.orgGeneration of multipartite photonic entanglement using a trapped-ion quantum processing nodeThe ability to establish entanglement between the nodes of future quantum networks is essential for enabling a wide range of new applications in science and technology. A promising approach involves t...

In our new paper arxiv.org/abs/2510.15693, EntaQCT www.quitphysics.info/entaqct team member Ida Mishra and myself on the side of @tuwien.at had the pleasure of collaborating with the team of Ben Lanyon at the @uniinnsbruck.bsky.social 4/8

GME is a non-classical correlation between multiple nodes that is required to make full use of the potential advantages of such a quantum network. While the quantum systems at the end nodes will likely have to be matter based, light signals are the only viable option for the distribution. 2/8