added the pointers to claims of realizing quantum supremacy:

F. Arute et al.

*Quantum supremacy using a programmable superconducting processor*, Nature**574**(2019) 505–510 (doi:10.1038/s41586-019-1666-5)Han-Sen Zhong et al. ,

*Quantum computational advantage using photons*, Science**370**6523 (2020) 1460-1463 (doi:10.1126/science.abe8770 )

and some review:

Adrian Cho,

*Google claims quantum computing milestone*, Science**365**6460 (2019) 1364 (doi:10.1126/science.365.6460.1364)Philip Ball,

*Physicists in China challenge Google’s “quantum advantage”*, Nature**588**380 (2020) (doi:10.1038/d41586-020-03434-7)

Added a bunch of very recent reviews:

*Quantum Computing Review Q4 2020*, IDQ January 2021Jiajun Chen,

*Review on Quantum Communication and Quantum Computation*, Journal of Physics: Conference Series, Volume 1865, 2021 International Conference on Advances in Optics and Computational Sciences (ICAOCS) 2021 21-23 January 2021, Ottawa, Canada (doi:10.1088/1742-6596/1865/2/022008)David Matthews,

*How to get started in quantum computing*, Nature**591**March 2021 (nature:d41586-021-00533-x, pdf)Christine Middleton,

*What’s under the hood of a quantum computer?*, Physics Today, March 2021 (doi:10.1063/PT.6.1.20210305a)

and some still fairly recent:

Qiang Zhang, Feihu Xu, Li Li, Nai-Le Liu, Jian-Wei Pan,

*Quantum information research in China*, Quantum Sci. Technol. 4 040503 (doi:10.1088/2058-9565/ab4bea)Farzan Jazaeri, Arnout Beckers, Armin Tajalli, Jean-Michel Sallese,

*A Review on Quantum Computing: Qubits, Cryogenic Electronics and Cryogenic MOSFET Physics*(arXiv:1908.02656)

I have added little comments on

“classical control/quantum data”,

quantum programming languages as linear type theory

the combination: dependent linear type theory as the language for classically controlled quantum computation

A reference on a recent experimental achievement.

- Han-Shen Zhong et al.
*Quantum computational advantage using photons*, Science 370, n. 6523 (2020) 1460-1463 doi

added this more recent survey:

- National Academies of Sciences, Engineering, and Medicine,
*Quantum Computing: Progress and Prospects*, The National Academies Press 2019 (doi:10.17226/25196)

added this more recent review:

- Eric C. Rowell, Zhenghan Wang,
*Mathematics of Topological Quantum Computing*, Bull. Amer. Math. Soc. 55 (2018), 183-238 (arXiv:1705.06206, doi:10.1090/bull/1605)

[ah, wrong entry, moved now to *topological quantum computing*]

added this pointer:

- Jens Eisert, M. M. Wolf,
*Quantum computing*, In:*Handbook of Nature-Inspired and Innovative Computing*, Springer 2006 (arXiv:quant-ph/0401019)

added to *quantum computation* an explicit pointer to the article

- Ugo Dal Lago, Claudia Faggian, On Multiplicative Linear Logic, Modality and Quantum Circuits (arXiv:1210.0613)

which argues explicitly that linear (modal) logic is a good formalization of quantum compuation.

But I need to stare at that article a bit more to get a better idea of what their modality does. Adding qbits? I am not sure if I got the point here.

]]>added this reference here to *quantum computation*

- Ross Duncan,
*Types for quantum mechanics*, 2006 (pdf)

and slightly re-arranged and briefly commented on the items in the list of references

(all still very stubby)

]]>I have added to the references at *quantum computation* and at *monad (in computer science)* and at *functional programming* a pointer to

- Thorsten Altenkirch, Alexander Green, The quantum IO monad, in Semantic Techniques in Quantum Computation, January 2009, appeared in 2010

I was convinced that John had discussed this as one of the topics planned for Azimuth Project, but my search did not find any directly related entry there, maybe John wrote about it elsewhere ? To some extent it s related to

- John C. Baez, Mike Stay,
*Physics, topology, logic and computation: a rosetta stone*, arxiv/0903.0340

which I will quote in the entry. The first ideas on quantum computing were due a paper of Feynman I think, but can not search for it now.

]]>stub for *quantum computation*