Great way to understand how operating systems work, which Ciro Santilli used extensively in his Linux Kernel Module Cheat.
Ciro Santilli has some good related articles listed under: Section "The best articles by Ciro Santilli".
The official hello world is documented at: qiskit.org/documentation/intro_tutorial1.html and contains a Bell state circuit.
Our version at qiskit/hello.py.
Quantum algorithm vs quantum gate vs quantum circuit by 
Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01There is no fundamental difference between them, a quantum algorithm is a quantum circuit, which can be seen as a super complicated quantum gate.
These appear to be benchmarks that don't involve running anything concretely, just compiling and likely then counting gates:
Quantum computing computational chemistry algorithms by Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01It is hard to beat the list present at Quantum computing report: quantumcomputingreport.com/players/.
The much less-complete Wikipedia page is also of interest: en.wikipedia.org/wiki/List_of_companies_involved_in_quantum_computing_or_communication It has the merit of having a few extra columns compared to Quantum computing report.
- Paulo Nussenzveig physics researcher at University of São Paulo. Laboratory page: portal.if.usp.br/lmcal/pt-br/node/323: LMCAL, laboratory of coherent manipulation of atoms and light. Google Scholar: scholar.google.com/citations?user=FbGL0BEAAAAJ
- Brazil Quantum: interest group created by students. Might be a software consultancy: www.terra.com.br/noticias/tecnologia/inovacao/pesquisadores-paulistas-tentam-colocar-brasil-no-mapa-da-computacao-quantica,2efe660fbae16bc8901b1d00d139c8d2sz31cgc9.html
- DOBSLIT dobslit.com/en/the-company/ company in São Carlos, as of 2022 a quantum software consultancy with 3 people: www.linkedin.com/search/results/people/?currentCompany=%5B%2272433615%22%5D&origin=COMPANY_PAGE_CANNED_SEARCH&sid=TAj two of them from the Federal University of São Carlos
- computacaoquanticabrasil.com/ Website half broken as of 2022. Mentions a certain Lagrange Foundation, but their website is down.
- QuInTec academic interest group
- www.terra.com.br/noticias/tecnologia/inovacao/pesquisadores-paulistas-tentam-colocar-brasil-no-mapa-da-computacao-quantica,2efe660fbae16bc8901b1d00d139c8d2sz31cgc9.html mentions 6 professors, 3 from USP 3 from UNICAMP interest group:
- drive.google.com/file/d/1geGaRuCpRHeuLH2MLnLoxEJ1iOz4gNa9/view white paper gives all names
- Celso Villas-Bôas
- Frederico Brito
- Gustavo Wiederhecker
- Marcelo Terra Cunha
- Paulo Nussenzveig
- Philippe Courteille
- sites.google.com/unicamp.br/quintec/home their website.
- a 2021 symposium they organized: www.saocarlos.usp.br/dia-09-quintec-quantum-engineering-workshop/ some people of interest:
- Samuraí Brito www.linkedin.com/in/samuraí-brito-4a57a847/ at Itaú Unibanco, a Brazilian bank
- www.linkedin.com/in/dario-sassi-thober-5ba2923/ from wvblabs.com.br/
- www.linkedin.com/in/roberto-panepucci-phd from en.wikipedia.org/wiki/Centro_de_Pesquisas_Renato_Archer in Campinas
- Quanby quantum software in Florianópolis, founder Eduardo Duzzioni
- thequantumhubs.com/category/quantum-brazil-news/ good links
- qubit.lncc.br/?lang=en Quantum Computing Group of the National Laboratory for Scientific Computing: pt.wikipedia.org/wiki/Laboratório_Nacional_de_Computação_Científica in Rio. The principal researcher seems to be www.lncc.br/~portugal/. He knows what GitHub is: github.com/programaquantica/tutoriais, PDF without .tex though.
- quantum-latino.com/ conference. E.g. 2022: www.canva.com/design/DAFErjU3Wvk/2xo25nEuqv9O7RbCPLNEkw/view
Quantum electrodynamics bibliography by Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01fafnir.phyast.pitt.edu/py3765/ Phys3765 Advanced Quantum Mechanics -- QFT-I Fall 2012 by E.S. Swanson mentions several milestone texts including:
Complex coordinate space of dimension 2 by Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01This section is about the definition of the dot product over , which extends the definition of the dot product over .
Some motivation is discussed at: math.stackexchange.com/questions/2459814/what-is-the-dot-product-of-complex-vectors/4300169#4300169
Just like the usual dot product, this will be a positive definite symmetric bilinear form by definition.
Experiments explained by QED but not by the Dirac equation:
- Lamb shift: by far the most famous one
- hyperfine structure TODO confirm
- anomalous magnetic dipole moment of the electron
Quantum entanglement is often called spooky/surprising/unintuitive, but they key question is to understand why.
To understand that, you have to understand why it is fundamentally impossible for the entangled particle pair be in a predefined state according to experiments done e.g. where one is deterministically yes and the other deterministically down.
In other words, why local hidden-variable theory is not valid.
How to generate entangled particles:
- particle decay, notably pair production
- for photons, notably: spontaneous parametric down-conversion, e.g.: www.youtube.com/watch?v=tn1sEaw1K2k "Shanni Prutchi Construction of an Entangled Photon Source" by HACKADAY (2015). Estimatd price: 5000 USD.
Contains the clearest Bell test experiment description seen so far.
It clearly describes the photon-based 22.5, 45 degree/85%/15% probability photon polarization experiment and its result conceptually.
It does not mention spontaneous parametric down-conversion but that's what they likely hint at.
Done in Collaboration with 3Blue1Brown.
Question asking further clarification on why the 100/85/50 thing is surprising: physics.stackexchange.com/questions/357039/why-is-the-quantum-venn-diagram-paradox-considered-a-paradox/597982#597982
Quantum Mechanics: Animation explaining quantum physics by Physics Videos by Eugene Khutoryansky (2013)
Source. Usual Eugene, good animations, and not too precise explanations :-) youtu.be/iVpXrbZ4bnU?t=922 describes a conceptual spin entangled electron-positron pair production Stern-Gerlach experiment as a Bell test experiments. The 85% is mentioned, but not explained at all.Quantum Entanglement Lab by Scientific American (2013)
Source. The hosts interview Professor Enrique Galvez of Colgate University who shows briefly the optical table setup without great details, and then moves to a whiteboard explanation. Treats the audience as stupid, doesn't say the keywords spontaneous parametric down-conversion and Bell's theorem which they clearly allude to. You can even them showing a two second footage of the professor explaining the rotation experiments and the data for it, but that's all you get.- web.archive.org/web/20150623011722/http://users.physik.fu-berlin.de/~kleinert/b6/psfiles/qft.pdf by Hagen Kleinert (2015). 1500 pages!
- The Quantum Theory of Fields by Steven Weinberg (2013) www.cambridge.org/core/books/quantum-theory-of-fields/22986119910BF6A2EFE42684801A3BDF
- Quantum Field Theory by Lewis H. Ryder 2nd edition (1996) www.amazon.co.uk/Quantum-Field-Theory-Lewis-Ryder/dp/0521478146
- Lectures of Quantum Field Theory by Ashok Das (2018) www.amazon.co.uk/Lectures-Quantum-Field-Theory-Ashok-ebook/dp/B07CL8Y3KY
- A Modern Introduction to Quantum Field Theory by Michele Maggiore (2005) www.amazon.co.uk/Modern-Introduction-Quantum-Theory-Physics/dp/0198520743
Quantum Field Theory book by Mark Srednicki (2006) by Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01Free to view draft: web.physics.ucsb.edu/~mark/ms-qft-DRAFT.pdf Page presenting it: web.physics.ucsb.edu/~mark/qft.html
Number of pages: 616!
Don't redistribute clause, and final version by Cambridge University Press, alas, so corrections will never be merged back: web.physics.ucsb.edu/~mark/qft.html. But at least he's collecing erratas for the published (and therefore draft) versions there.
The preface states that one of its pedagogical philosophies is to "Illustration of the basic concepts with the simplest examples.", so maybe there is hope after all.
Quantum field theory in a nutshell by Anthony Zee (2010) by Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-04-18 +Created 1970-01-01 Pinned article: ourbigbook/introduction-to-the-ourbigbook-project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
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