An article based on interviews with Quantum Machines and Nvidia about how they used reinforcement learning to optimize pulses, improving performance and fidelity

https://techcrunch.com/2024/11/02/quantum-machines-and-nvidia-use-machine-learning-to-get-closer-to-an-error-corrected-quantum-computer/

Morning everyone. I am trying to define an algorithm which receives in input a parameterization of any form (for example a matrix) and convert it to a valid parameterization for the chi representation of a (P.S. CPTP) quantum channel. While I can do it for a subset of chi matrices I am not sure for the general setting, i.e. allowing the algorithm to map parametrizations to the whole set of chi matrices associated to CPTP maps (of some fixed dimension). Any suggestion?

Hey all - I made this video (it is sponsored just a disclosure) on the Variational quantum eigensolver. I hope some of yall find it useful!

Also feel free to leave any suggestions, I’m continuously trying to improve these so outside perspectives can be super helpful.

The Quantum Algorithm That Could Make Big Pharma Billions https://youtu.be/Fvwyd0536Gc

Hi everyone,

Since I received an offer for a PhD in the field, I would like to know the possibilities and job prospect post PhD (I do want to explore the field but possibly in industry)

Would love to know your opinions!

Hi everyone,

I'm curios to know if there exist courses/master in the field of quantum computing (also expensive ones) that one can follow remotely (I arealdy work as RF engineer).

While I have the possibility of pursuing a PhD in quantum computing, I don't feel confortable in leaving my job and was wondering if there are coruses and certifications which can be acknowleged from the community.

I personally believe wave-particle duality is a junk concept, clearly a confused notion using classical physics language (which was the only language available), and stretched to the limit by DeBroglie & Schrödinger at the request of Einstein.

There is no wave. The Schrödinger equation is not a wave equation (it's a 3D complex diffusion equation), and solutions only look wave-like in very limited cases. Particles I have no issue with, as upon measurement objects certainly appear particle-like.

What I wonder is why we don't have "field-particle duality". This also utilizes the dominant terminology of the early 20th Century, and appears more precise: wavefunctions have a complex amplitude at every point in space, which changes over time.

Do you think it's reasonable to teach "field-particle duality" to early-level undergraduates (here I'm taking about non-relativistic QM, obviously QFT deals with this), or do I still fall into a trap of poor terminology?

I was woindering how many of you guys work in this field and most importantly are you satisfied with the work/life balance and money you make?

I know that many of the people that approach this field (especially from the research part) would be interested in pushing the boundaries of knowledge etc.. but I do think that highly specialised people in such field are unique for their skillset and since they are not so many, this could bring the market to value them the most. Is this true in industry ora not?

Love to know you experiences/ stories!

I am an decent software engineer with 18 years experience. I want to learn quantum computing or engineering. Start working in it. I want to learn play around and get a job in it. If anyone can suggest any courses both free and paid? Any good books? It would be really helpful. Thanks.

Hello all. I'm preparing for my qualifying exam and my research deals with mixture vs superposition. Since I'm in a chemistry PhD program, I'm trying to find a good chemical metaphor for both of these. My initial thought was using a benzene ring to describe the pure state and a beaker of evenly mixed isomers to describe the mixed state. The thinking goes like: if we measure a single carbon for an electron on the benzene ring, there's a 50/50 chance we'll find one, just as if we measure a single molecule from the beaker we'll find one of the isomers with a 50/50 chance. The difference is we can change the basis of measurement in the benzene ring to bond strength and with probability 1 measure a bond strength of 1.5x a C-C bond. There is no measurement coordinate for the beaker (pick two molecules out, only pick from the right/left side, measure the attraction between two random molecules, etc.) which will guarantee an outcome. My next metaphor is light polarization. Suppose you have two boxes, one containing a whole bunch of photons known to be in a superposition of vertical and horizontal polarization (for the sake of argument let's say its a sum, not a difference) and the second containing unpolarized light. If we put a vertical filter in front of both boxes, we won't find any difference between our measurements. half from each box will be vertical and half will be horizontal. however, if we put a counterclockwise polarizing filter in front of each box, the first box will yield 100% photons in counterclockwise polarization and 0% in clockwise. On the other hand, the second box will still give us a 50/50 shot at either? Can someone help me find a better metaphor before my advisor comes back? I'm afraid I don't have the analogy skills of Feynman.

I'm looking for a book that will take a beginners that know almost nothing to an experts if something like that even exists

If proton converts to nuetron by emitting a meson and vice versa, then how can we say that number of protons in a nucleus is always constant, as at any instant there can be more less or equal protons as compared to original configaration

Hello! I am a recent graduate of an Engineering Physics Bachelor Degree and I am trying to find a masters program that suits my interests. So far I have found:

Waterloo - Electrical and Computer Engineering (Quantum Information) Master of Applied Science (MASc)

KTH - Masters in Engineering Physics, Quantum Technology Track

Does anyone know of any other engineering masters programs that focus on quantum engineering? My goal is to get a practical degree that will allow me to get into the quantum computing industry!

From what I understand, anything that interacts with the photon causes it to be "observed" and the waveform to collapse. I understand why the screen is an observer-- the photon is hitting it. However, clearly the double-slit itself is also interacting with the photon, and is hit by the photon as a waveform. So why does the waveform not collapse at this first interaction, and only collapses when it hits the second object (the screen)?

Just to check Light is a particle and wave AND And a particle is light and contributions to mass? Is that the only way to view the entropy, through photons?

I have a link that I heard this from, I'm a newbie about cosmic background scattering

https://youtu.be/PbmJkMhmrVI?si=uk7s1s-yEyGnqHGZ

18:40 to 19:00 is where she says it

Hello everyone,

I’m a science fiction writer currently conducting research for a project, and I’m looking to understand the empirical/concrete aspects of quantum experiments—especially those involving entanglement and quantum state detection.

I’m in search of visual resources (videos, documentaries, or articles with images) that break down how these experiments are done in practice.

Specifically, I’m seeking:

1. Real-world setups that generate quantum entanglement (e.g., through SPDC using nonlinear crystals).
2. Detectors (like APDs and PMTs) used for measuring quantum properties at a distance, with an emphasis on how they are implemented in modern experiments.
3. Beam splitters and optical components—how they are optimized for entanglement experiments and to avoid decoherence.
4. The materials and designs behind the lasers used to manipulate quantum systems and achieve precise outcomes.
5. Practical demonstrations or modern applications, such as quantum sensing, quantum cryptography, or quantum communication, where these technologies are put to use.

I’m hoping to find resources that visually demonstrate the construction and operation of these systems, giving a clear view of how quantum properties are measured and manipulated in experimental settings. If you have any suggestions for documentaries, videos, or articles that provide this level of detail, I’d greatly appreciate it!

Thanks for your help!

The 2024 Quantum Open Source Software Survey through Unitary Fund is here! https://www.surveymonkey.com/r/qosssurvey24

Covering topics like demographics, experience, community, research, and tech stacks, this annual survey is a chance for anyone in quantum computing to add their voice to the development of our field to share feedback, state your needs, and take part in shaping the future of the quantum computing ecosystem.

The survey will be available through the end of October. All anonymized results will be shared publicly later this year, so that this may be a resource for anyone who wants a better understanding of the quantum computing community’s needs.

Hi,

We are nearing completion, if you'd like to help us find bugs or have some interesting ideas about what educational modules we should add in, drop me a DM/ write here and I will send you a free key!

Algos we cover so far: BV, Grover, Shor, QFT/ Inverse QFT

https://store.steampowered.com/app/2802710/Quantum_Odyssey/

So, I'm trying to learn some quantum mechanics from "a modern approach to quantum mechanics" by John S. Townsend. Overall it's a great book, but there are some parts in it which use circular reasoning to derive the angular momentum matrices for a spin-1 particle. (This is chapter 3 in the book). Basically the argument goes like this:

1. Assume that the angular momentum operators Sz, Sy and Sx have a specific matrix form in the z basis. (Don't worry about how we got these matrices for now).
2. Using the matrix form we derive the commutation relations of the angular momentum operators [Sx,Sy] = ihSz , etc... (h here means hbar)
3. Define the raising and lowering operators as S+ = Sx + i Sy and S- = Sx - iSy
4. Using the commutation relations in step 2 and the definition of the raising and lowering operators we derive the action of these operators on eigenstates of Sz.
5. Based on the action of the raising/lowering operators on an eigenstate of Sz as well as their definition in terms of Sx and Sy, express Sx and Sy in terms of the raising and lowering operators. This tells you what the action of Sx and Sy is on eigenstates of Sz.
6. Now you can derive the matrix expression of Sx in the z basis by computing the i,j th matrix element which take the form <1,i|Sx|1,j> for the operator Sx, for instance.
7. Done!

BUT WAIT!

In order to start this whole argument we already began with the matrix forms of Sx and Sy in the z basis! In other words, the whole argument given in Townsend is circular unless there is some other way to derive the commutation relations of Sx, Sy and Sz without using any of the things that are derived from them (so nothing to do with the raising and lowering operators) and also not by using the matrix forms of these operators.

So my question is: Is this possible? Can you derive the commutation relations of Sx, Sy and Sz without using any of the things that are derived from them (so nothing to do with the raising and lowering operators) and also not by using the matrix forms of these operators? Or is the only way to do this to resort to experimental observations?

Any help or clarification would be greatly appreciated!

Edit: Ok, I think I get it now:

Townsend actually does derive the commutation relation. He derives them at the start of chapter 3. Basically he explicitly computes the commutation relations of rotation matrices of vectors about the z, x and y axes. This is just basic trigonometry and vector algebra.

He then replaces these rotation matrices with rotation operators (which involve the angular momentum operators). He then expands the operators as a Taylor series for small angles and equates the terms. The commutation relations of the angular momentum operators then drop out automatically.

Ok, I believe it now.

https://www.reddit.com/r/u_cjosefschneider/comments/1fk3uzf/i_want_read_some_books_about_nuclear_physics_and/

If particle interactions have been happening since the Big Bang, could this mean the wave function has been collapsing continuously due to these interactions?

Does this imply that particles themselves define each other’s states through these interactions, without the need for external observers?

How does this fit into our understanding of quantum mechanics on a universal scale?

I am not looking for textbook suggestions but if some textbook is available only on Internet, I'd like to go through it. I'm specifically looking for top quality online content which can't be found through Google searches. Any suggestions?

I always thought superposition was a indication of a possible multiverse, and asumed it was infinite, but wouldnt the entire bar have lit up? The only exception i see is that if in one of these alternate universes perhaps the results slightly differ, still allowing infinite universes through thier differences.

So sleepy now, im probably wrong anyway.

I just started a bachelor's degree in mathematics. My original intention was to study physics, but due to a series of events, I ended up in math—and I’m loving it. However, my deepest interest still lies in quantum physics, a subject I barely grasp. My question is: is a degree in math a solid foundation for continuing studies in theoretical physics later on? Thank you all in advance.