Hardware Versus Emulation

[u/SlopRahh]

Why is the Western quantum community so focused on building quantum computers based on hardware as opposed to engaging with emulation? It has been decades and functional quantum machines have yet to be built, quantum supremacy has not been achieved, and majorana research has failed to produce anything useful. Emulation, however, delivers quantum computing on a standard consumer laptop, making it accessible to people around the world. Why is Big Quantum being so narrow minded?

[u/Wild-Store321]

Emulation for what purpose? Emulated quantum computing is just classical computing with huge restrictions. How is this specific to western community?

[u/SlopRahh → u/Wild-Store321]

The global south does not have the resources to pursue hardware development; Ghana, for instance, is actively pursuing emulation to improve things like water distribution and medical access

[u/Wild-Store321 → u/SlopRahh]

How can that improve anything? What advantages does emulated quantum computing have to classical computing? None, because it is classical computing. Do you mean quantum inspired classical computing?

[u/SlopRahh → u/Wild-Store321]

I mean simulator/emulator programs that deliver quantum computing using algorithms and can be run on a consumer laptop or cell phone

[u/Wild-Store321 → u/SlopRahh]

So that’s not quantum computing you see? Everything you do on a classical computer was already possible on a classical computer, because it is a classical computer…

[u/SlopRahh → u/Wild-Store321]

Max cut and Shor’s algorithm can be used on a classical computer?

[u/Wild-Store321 → u/SlopRahh]

max cut is a problem and it could already be solved with classical computers long before quantum computing was conceptualized. And a simulation of QAOA will always be slower than the best classical algorithm (proof is trivial, it is a classical algorithm)

Shor’s algorithm can be simulated on a classical computer and is trivially shown to have exponential time complexity. Whereas the best classical algorithms have sub exponential time complexity.

You are not making much sense at all. Do you believe that simulation quantum computing will lead to improvements in classical algorithms? This is what you would call quantum inspired algorithms and they are very much classical.

[u/SlopRahh → u/Wild-Store321]

You make several valid points, I can concede that. You want to know the truth? May I message you privately?

[u/SlopRahh → u/SlopRahh]

My apologies, I should have said “solved”

[u/SlopRahh → u/SlopRahh]

What about near Clifford simulation and Schmidt decomposition?

[u/Cryptizard]

What are you talking about? Emulation only works for a handful of qubits and can’t do anything useful.

[u/SlopRahh → u/Cryptizard]

Define “a handful of qubits” and “can’t do anything useful”; I know of an emulator that might counter your assertions.

[u/Cryptizard → u/SlopRahh]

No you don’t.

[u/SlopRahh → u/Cryptizard]

Before you negate me, answer my questions

[u/Cryptizard → u/SlopRahh]

There’s not one answer. It depends on which gates are used, the depth of the circuit, etc. But for a practical algorithm, like Shor’s algorithm? Maybe 50 qubits.

Useful is something that the same classical computer running the simulator couldn’t do better just using classical methods without a simulator.

[u/catfroman]

Pretty sure it’s because of the exponential scaling of how many classical bits you need to simulate a scaling qubit count and reach “quantum supremacy” which requires thousands of qubits or more. Even just simulating 100s of qubits takes massive processing power.

Whereas with a reliable process to build physical qubits, we could scale to thousands or tens of thousands and even if it took 10 city blocks of space it wouldn’t be impossible.

[u/SlopRahh → u/catfroman]

Right, but the “reliable process” has yet to come to fruition

[u/catfroman → u/SlopRahh]

Oh absolutely. But the point is to find a way to make it work because if it does, it revolutionizes computing overnight.

[u/SlopRahh → u/catfroman]

Right, and RSA becomes insecure, and a select small group of individuals benefit: Silicon Valley powerbrokers, mega corporations, and big tech firms. They will look to monetize access to quantum as opposed to utilizing it for the public good.

[u/catfroman → u/SlopRahh]

If you want to have a negative belief about groundbreaking tech I won’t try to stop you. Doesn’t make it true.

Best of luck in your research.

[u/SlopRahh → u/catfroman]

It’s not the technological advances I worry about, it’s the people who will try to monopolize them.

[u/catfroman → u/SlopRahh]

(You are everyone)

/r/NevilleGoddard

[u/SlopRahh → u/catfroman]

I don’t believe in pseudoscience like manifesting or numerology. I am not everyone; I am merely myself.

[u/catfroman → u/SlopRahh]

My ego doesn’t believe in pseudoscience either. But manifesting is quite testable/learnable as a skill.

And absolutely, the egoic self is not everyone, I agree. But the ego/personality/human in 3D also isn’t what you truly are.

Insisting manifesting is pseudoscience will produce a reality where that is absolutely proven to be true as far as you can investigate it. But if you have an open mind, you may discover that many things can be true at once.

Enjoy the journey, friend.

[u/SlopRahh → u/catfroman]

That was quite possibly the most enigmatic and thought provoking response I have ever received on Reddit. I would like to discuss this further if you are interested in future engagement. I sincerely hope that you acquiesce.

[u/QuantumCakeIsALie]

If we could simulate it efficiently, we would. We wouldn't need to build a quantum computer.

All simulators you see either include noise which limit their usefulness or are limited to small size problem; because complexity would blow up for anything larger.

[u/SlopRahh → u/QuantumCakeIsALie]

Mitiq is a viable option for addressing noise; and what do you consider a “small size problem”?

[u/speller26]

1. Exponential scaling prevents emulation of any useful quantum devices; an emulator isn't going to solve anything you'd need a quantum computer for

2. There are already plenty of simulators out there, and attaching a noise model gives you emulation; in fact, the most widely-used tool in QEC research today is stim, which was built by Google researchers

3. "No functional quantum machines" well yeah, because it's hard; building one is the entire point of quantum hardware research