ASML Holding by Ciro Santilli 37 Updated 2025-07-16
As of 2020 leading makers of the most important fab photolithography equipment.
Video 1.
ASML: TSMC's Critical Supplier by Asianometry (2021)
Source.
Video 2.
How ASML Won Lithography by Asianometry (2021)
Source.
First there were dominant Elmer and Geophysics Corporation of America dominating the market.
Then a Japanese government project managed to make Nikon and Canon Inc. catch up, and in 1989, when Ciro Santilli was born, they had 70% of the market.
youtu.be/SB8qIO6Ti_M?t=240 In 1995, ASML had reached 25% market share. Then it managed the folloging faster than the others:
Arm (company) by Ciro Santilli 37 Updated 2025-07-16
Video 1.
Arm 30 Years On: Episode One by Arm Ltd. (2022)
Source.
Video 2.
Arm 30 Years On: Episode Two by Arm Ltd. (2022)
Source.
Video 3.
Arm 30 Years On: Episode Three by Arm Ltd. (2022)
Source. This one is boring US expansion. Other two are worth it.
Qualcomm by Ciro Santilli 37 Updated 2025-07-16
Ciro Santilli has always had a good impression of these people.
Reverse transcriptase by Ciro Santilli 37 Updated 2025-07-16
Converts RNA to DNA, i.e. the inverse of transcription. Found in viruses such as Retrovirus, which includes e.g. HIV.
Radio receiver by Ciro Santilli 37 Updated 2025-07-16
As well put by Wikipedia, a radio receiver has to perform three functions on the signal from the antenna:
Qiskit by Ciro Santilli 37 Updated 2025-07-16
Python library, claims multiple backends, including simulation and real IBM quantum computer.
Just like as for classic gates, we would like to be able to select quantum computer physical implementations that can represent one or a few gates that can be used to create any quantum circuit.
Unfortunately, in the case of quantum circuits this is obviously impossible, since the space of N x N unitary matrices is infinite and continuous.
Therefore, when we say that certain gates form a "set of universal quantum gates", we actually mean that "any unitary matrix can be approximated to arbitrary precision with enough of these gates".
Or if you like fancy Mathy words, you can say that the subgroup of the unitary group generated by our basic gate set is a dense subset of the unitary group.
E91 by Ciro Santilli 37 Updated 2025-07-16
Requires entangled particles, unlike BB84 which does not.
TODO holy crap, even this is hard to understand/find a clear definition of.
The Dirac equation, OK, is a partial differential equation, so we can easily understand its definition with basic calculus. We may not be able to solve it efficiently, but at least we understand it.
The formulation of QFT also appears to be a form of infinite-dimentional calculus.
Quantum electrodynamics by Lifshitz et al. 2nd edition (1982) chapter 1. "The uncertainty principle in the relativistic case" contains an interesting idea:
The foregoing discussion suggests that the theory will not consider the time dependence of particle interaction processes. It will show that in these processes there are no characteristics precisely definable (even within the usual limitations of quantum mechanics); the description of such a process as occurring in the course of time is therefore just as unreal as the classical paths are in non-relativistic quantum mechanics. The only observable quantities are the properties (momenta,
polarizations) of free particles: the initial particles which come into interaction, and the final particles which result from the process.

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