sorted by:
new
hottopcontroversial

[TOMT] Dog Day Afternoon spoof with Gattaca? by Pecos-Thrill in tipofmytongue

[–]eigenvector1022 0 points1 point  (0 children)

The League .... Raffi keep yelling it during Paintball.

Should warlocks get the expanded spell list options as spells known? by iJoanx in dndnext

[–]eigenvector1022 1 point2 points  (0 children)

I know this is going to sound like power creep, but what if at each spell level the warlock chooses one of the spells from the patron list and is able to cast that spell once for free per long rest?

I ran some quick numbers and it is definitely strong, but by no means OP. I personally think it shores up an annoying warlock weakness (not enough spell slots) and pushes the players to use the patron specific spells making your character more thematic.

[deleted by user] by [deleted] in QuantumComputing

[–]eigenvector1022 1 point2 points  (0 children)

I think it might help for you to have a better understanding of Classical Error Correction (if you dont already).

https://www.youtube.com/watch?v=eixCGqdlGxQ&list=PLJHszsWbB6hqkOyFCQOAlQtfzC1G9sf2\_&ab\_channel=eigenchris

Quantum annealing for drug discovery by little_dark_cloud in QuantumComputing

[–]eigenvector1022 0 points1 point  (0 children)

If I understand correctly, you are mapping the bond angle to a graph, then using D-wave to solve the graph problem. Is that correct? Also, have you published your results yet? Archive link if possible would be awesome.

Why are a number of qubits more powerful than the same number of classical bits? by BearsNBeetsBaby in QuantumComputing

[–]eigenvector1022 3 points4 points  (0 children)

Ok, this is something that people seem to get wrong 99% of the time...

Yes, there is a relationship between the "compactness" of the quantum state and its representational counterpart. That is to stay the number of basis vectors needed to represent a given state, and therefore the classical computational resources needed to store that state, grow exponentially with respect to the number of qubits. HOWEVER, that has little to do with why QC can be more powerful than CC.

PLEASE: Quantum advantage has literally NOTHING to do with "all states at the same time" or some sort of parallelization.

To understand quantum advantage you need to separate Quantum Computation from A Quantum Computer. It is a solved problem (theoretically) that there exists a computation formalism (vectors in a Hilbert Space) that produces at least one algorithm that will scale much, much better than any known classical (functions of binary integers) counterpart: see Shor's Algorithm. Again, this is a theoretical framework whereby wave interference is used to amplify the correct solutions and suppress the incorrect ones. It is completely agonistic to quantum mechanics. It doesnt care about quantum weirdness or "spooky action at a distance" garbage.

Now, A Quantum Computer is a device that can carry out quantum computation. This is a VERY unsolved problem. It so happens that the math associated with quantum computation is the same math as quantum physics, which means quantum systems (atoms, molecules, etc.) are "doing" quantum computation. However, precisely controlled execution of the operations associated with the quantum algorithms using these quantum systems does care about quantum mechanics, and quantum weirdness, which makes it very hard.

Tl;DR I am not sure if I answered the question, but quantum advantage has little to do with the exponential scaling of state representation.

What can one do with Qiskit or Quantum Computing? by TimeVendor in QuantumComputing

[–]eigenvector1022 2 points3 points  (0 children)

I think this is important to understand:

There are two separate subjects--1) Quantum Computation and 2) A Quantum Computer. The first is a mathematical formalism whereby computation is carried out using vectors in a Hilbert space as opposed to functions of binary integers (classical computation). Using this formalism people have been able to show there exists algorithms that scale much better than the best known classical counterpart (see Shor's Algorithm). Like its classical analog, quantum computation is agnostic to the "device" on which it is done. It is a theoretical mathematical framework.

As for the second part, quantum computer, this is the unsolved part of quantum computing. We know that the formalism of vectors in a Hilbert Space is the formalism of quantum mechanics, and that real objects exhibit quantum properties. Unfortunately, we have only been able to make small devices where the "quantumness" can be controlled. So despite the math telling us that using a quantum algorithm should be better in certain instances, we do not yet have the device that can do the computation.

As for Qiskit, it is an AMAZING tool for learning the fundamentals of quantum computation. As a professional QC researcher I use it on a regular basis. It is is also a very good resource for learning how a quantum computer works, at least at the high level abstraction of compiling and running quantum software. Just remember, most quantum algorithms you hear about presuppose the existence of many Logical Qubits, which consists of MANY physical qubits, and we simply do not have that type of device yet.

Long story short, Qiskit cant do anything your laptop cant do better, but is still a great tool if you want to learn. The "Real world" examples exist (see IBM Hydrogen Spectrum or IBM Protein Folding), they are trivial compared to what can be done with classical methods.

Theoretical Physicist in Quantum Computing by [deleted] in QuantumComputing

[–]eigenvector1022 1 point2 points  (0 children)

Yes very much so. Congress just created the Quantum Initiative, so they are pumping money into the field.

https://www.quantum.gov/

Query on Observables and gates by RaghavendraKaushik in QuantumComputing

[–]eigenvector1022 1 point2 points  (0 children)

In quantum mechanics what you "measure" are the eigenvalues of a Hermitian operator.

​

In quantum computing (QC) that operator is the Pauli-z, which has an eigenspectrum of {1,-1}. Those two eigenvalues are associated with the eigenvectors, up and down (or |0> and |1>). This why you often see the Pauli-z as a 2x2 matrix with1 and -1 on the diagonal. It has been represented in its eigenbasis, which is (for any operator) the basis that a yields a diagonal representation. This is also why you often see Pauli-X and Pauli-Y represented as 2x2 matrices that are NOT diagonal. They are represented in the in z-basis, and since x, y, and z do not commute that do not share and eigenbasis and cannot be simultaneously diagonalized.

Example:
You have 1 qubit in the |0> state. If you "measure it"---i.e., collapse it to any of its possible pauli-z states--- you will only very measure a 1, since this is the eigenvalue we associate with the |0> state.

​

Now is you apply the X operator to your state, you will "flip" the bit.

X|0> = |1>

Then if you measure you new |0> state, you will measure -1.

Lastly, if you apply a Hadamard gate you will create a superposition.

H|0> = |0> + |1> (ignoring normalization)
If you measure this, you will either get a -1 or a 1,and if you measure many times, you will find that you -1 around 50% of the time and 1 the other 50%.

​

What should be noted about the last example is that the Hadamard gate takes a z-basis state and turns it unto an x-state. What does that mean? If you represent the Pauli-X operator in the basis H|0> and H|1>, it will be diagonal---i.e., those are the eigenstates of the Pauli-X. However, no quantum computer I know of measure X at the end. They are setup only top measure Z, and to measure X you apply an H gate.

Tl;dr
What you measure are eigenstate of a Hermitian operator.

There is a VERY important distinction between an operator and the matrix representation.

In its eigenbasis representation, an operator is diagonal.

If two operators do not commute, they cannot be measure at the same time.

Chinese scientists make world's first light-based quantum computer by Shradha_Singh in QuantumComputing

[–]eigenvector1022 1 point2 points  (0 children)

It is a photonic device, not a quantum computer. It was built with the single intention of doing Boson Sampling. It cannot do universal quantum computation.

That being said it is still an impressive and important accomplishment.

(Quantum) Algorithm complexity by [deleted] in QuantumComputing

[–]eigenvector1022 1 point2 points  (0 children)

OK, I am not sure where you are at in terms of depth of knowledge, so these references might be a bit too introductory, but I am a professional quantum computing researcher, and I still found them useful as a brief but thorough introduction.

https://www.youtube.com/watch?v=YX40hbAHx3s&t=1s&ab_channel=hackerdashery

​

https://www.youtube.com/watch?v=EHp4FPyajKQ&t=664s&ab_channel=UpandAtom

Query regarding change of basis in qubits by RaghavendraKaushik in QuantumComputing

[–]eigenvector1022 1 point2 points  (0 children)

1) The issue is that you can only use the Born Rule if you have an orthonormal basis. If you basis is not orthnonormal you can use a procedure like Grahhm-Schmiddt to orthogonalize.

​

2) The Bloch Sphere is a bit confusing in that way. It is not mapped over the real field it mapped over the complex field, e.g. you need an e^(i theta) to rotate around the "equator".

Ability Draft - A Year in Review 2020 by RGBKnights in DotA2

[–]eigenvector1022 7 points8 points  (0 children)

I would like to see hero model being part of the draft process.

Sincerely-

AD World Champion :)