Noisy intermediate-scale quantum era by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Era of quantum computing before we reach physical errors small enough to do perfect quantum error correction as demonstrated by the quantum threshold theorem.
Relativistic Quantum Mechanics by Apoorva D Patel (2014) by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Quantum Field Theory lecture notes by David Tong (2007) by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Number of pages circa 2021: 155.
It should also be noted that those notes are still being updated circa 2020 much after original publication. But without Git to track the LaTeX, it is hard to be sure how much. We'll get there one day, one day.
Some quotes self describing the work:
- Perhaps for this reason Ciro Santilli was not able to get as much as he'd out of those notes either. This is not to say that the notes are bad, just not what Ciro needed, much like P&S:
In this course we will not discuss path integral methods, and focus instead on canonical quantization.
A follow up course in the University of Cambridge seems to be the "Advanced QFT course" (AQFT, Quantum field theory II) by David Skinner: www.damtp.cam.ac.uk/user/dbs26/AQFT.html
Quantum field theory in a nutshell by Anthony Zee (2010) by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
2s/2p energy split in the hydrogen emission spectrum, not predicted by the Dirac equation, but explained by quantum electrodynamics, which is one of the first great triumphs of that theory.
Note that for atoms with multiple electrons, 2s/2p shifts are expected: Why does 2s have less energy than 1s if they have the same principal quantum number?. The surprise was observing that on hydrogen which only has one electron.
Initial experiment: Lamb-Retherford experiment.
On the return from the train from the Shelter Island Conference in New York, Hans Bethe managed to do a non-relativistic calculation of the Lamb shift. He then published as The Electromagnetic Shift of Energy Levels by Hans Bethe (1947) which is still paywalled as of 2021, fuck me: journals.aps.org/pr/abstract/10.1103/PhysRev.72.339 by Physical Review.
The Electromagnetic Shift of Energy Levels Freeman Dyson (1948) published on Physical Review is apparently a relativistic analysis of the same: journals.aps.org/pr/abstract/10.1103/PhysRev.73.617 also paywalled as of 2021.
TODO how do the infinities show up, and how did people solve them?
Lamb shift by Dr. Nissar Ahmad (2020)
Source. Whiteboard Lecture about the phenomena, includes description of the experiment. Seems quite good.Murray Gell-Mann - The race to calculate the relativistic Lamb shift by Web of Stories (1997)
Source. Quick historical overview. Mentions that Richard Feynman and Julian Schwinger were using mass renormalization and cancellation if infinities. He says that French and Weisskopf actually managed to do the correct calculations first with a less elegant method.www.mdpi.com/2624-8174/2/2/8/pdf History and Some Aspects of the Lamb Shift by G. Jordan Maclay (2019)
Freeman Dyson - The Lamb shift by Web of Stories (1998)
Source. Mentions that he moved to the USA from the United Kingdom specifically because great experiments were being carried at Columbia University, which is where the Lamb-Retherford experiment was done, and that Isidor Isaac Rabi was the head at the time.
He then explains mass renormalization briefly: instead of calculating from scratch, you just compare the raw electron to the bound electron and take the difference. Both of those have infinities in them, but the difference between them cancels out those infinities.
Hans Bethe - The Lamb shift (1996)
Source. Selected Papers on Quantum Electrodynamics by Julian Schwinger (1958) by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Advanced quantum mechanics II by Douglas Gingrich (2004) by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
In three dimensions In position representation, we define it by using the gradient, and so we see that
Organization developing photonic quantum computer by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Infinitely many slits thought experiment by
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Mentioned for example in quantum field theory in a nutshell by Anthony Zee (2010) page 8.
PageRank was apparently inspired by it originally, given that.
When you fail a HR interview, then you know you've reached rock bottom.
Investments:
- 2024: 75m GBP
- 2023-04: 15m GBP: www.uktech.news/deep-tech/riverlane-series-b-20230424 At 100 employeed on LinkedIn, this should keep them going for two more years.
- 2022 500k GBP: www.uktech.news/deep-tech/riverlane-rigetti-quantum-innovate-uk-20220628 by Innovate UK for joing project with Rigetti Computing to work on quantum error correction
Consider the E. Coli K-12 MG1655 operon thrLABC.
That single operon can produce two different mRNA transcription units:
- thrL only, the transcription unit is also called thrL: biocyc.org/ECOLI/NEW-IMAGE?object=TU0-42486
- thrL + thrA + thrB + thrC all together, the transcription unit is called thrLABC: biocyc.org/ECOLI/NEW-IMAGE?type=OPERON&object=TU00178
The reason for this appears to be that there is a rho-independent termination region after thrL. But then under certain conditions, that must get innactivated, and then the thrLABC is produced instead.
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