Quantum Supremacy Using a Programmable Superconducting Processor

I'm seeing a lot of comments claiming this claim can't be trusted because there's no useful computation being done.

There are many competing proposals to test for quantum supremacy: Boson Sampling, Fourier Sampling, IQP, Random Circuit Sampling. The computation needs to meet certain requirements. Worst case hardness, average case hardness, anti-concentration. Also there needs to be a way to test to see if the output of the computation is correct. This is easier said than done. RCS is the only one that meets all three and can be verified.

What's happening here is a test of RCS: A general quantum gates are being programmed to generate a random circuit. Think about randomly connecting some components on a breadboard and then simulating what would happen. Except this is done programmatically. The question is to then predict the output with a classical computer. This can't be done easily.

For a deeper dive into RCS, see this paper: https://arxiv.org/pdf/1803.04402.pdf

>> In this paper we study both the hardness and verification of RCS. While RCS was defined with experimental realization in mind, we show complexity theoretic evidence of hardness that is on par with the strongest theoretical proposals for supremacy. Specifically, we show that RCS satisfies an average-case hardness condition – computing output probabilities of typical quantum circuits is as hard as computing them in the worst-case, and therefore #P-hard. Our reduction exploits the polynomial structure in the output amplitudes of random quantum circuits, enabled by the Feynman path integral. In addition, it follows from known results that RCS satisfies an anti-concentration property, making it the first supremacy proposal with both average-case hardness and anti-concentration.

This is just nonsense. It equivocates between two separate things by calling both of them "quantum interference":

1) A quantum computer uses computational gates to very deliberately orchestrate interference patterns. This is the reason quantum computers are faster than classical ones at certain problems.

2) On top of (1), there's a ton of undesired interference because of dirty real-world constraints. Quantum computers are not fully isolated from their environment, and executing a gate cannot be done without also affecting qubits that are not supposed to be part of the gate.

> subject to bias due to quantum interference, which they check by solving the path integral in classical simulation

This is an instance of (1)

> because quantum interference is EXACTLY WHY WE CAN’T USE CURRENT QUANTUM PROCESSORS TO “BREAK ALL CRYPTO” IN THE FIRST PLACE BECAUSE WE CANNOT DO EFFICIENT QUANTUM ERROR CORRECTING CODES

This is an instance of (2).

Quantum supremacy is all about showing that you can implement (1) with enough fidelity even in the presence of (2). Now keep this in mind while reading the rant again, and you'll quickly realize it's absolute nonsense.

Nailing down issues with fault tolerances are a whole lot different than pioneering methods and sciences of uncharted territory. I didn't generalize all technicalities, I specified fault tolerance for a reason, because it's trivial compared to what it took to get to this point. The system works, just not as well as it will take to get to reliable wide spread usage.

It is widely believed that implementing useful quantum error correction (if possible at all) will be orders of magnitude more difficult than what was done so far. To my knowledge, there is no realistic proposal how to implement it on any of the current platforms.

The Joshua Tree Quantum Computer Achieves Quantum Supremacy: Dr. Elliot McGucken's research group hath created a quantum computer capable of simulating over five sextillion atoms in the form of water molecules, performing massively complex calculations in a fraction of a second, leveraging quantum entanglement in the Hilbert Space, thusly tapping into the power of higher dimensions and the space of parallel universes. These highly complex many-body calculations would take classical computers over a trillion trillion trillion years to solve and simulate. The JT Quantum Computer leverages the quantum multiverse to generate random numbers and pattern distributions via the entangled interactions of five sextillion atoms.

Atoms in a drop of water = 3 atoms/molecule x 1.67 x 10^21 molecules = 5.01 x 10^21 atoms, or five sextillion atoms.

The patent-pending Joshua Tree Quantum Computer works as follows:

One obtains an eye-dropper and a glass of water.

One takes up a drop of water in the eye-dropper.

One drops said drop of water onto a flat piece of glass.

Immediately one achieves and observes the random pattern distribution based on the entangled interactions between the over 5.01 x 10^21 atoms (five sextillion atoms), as the combined wave function collapses and the universe splits a trillion trillion times. Using a classical computer, one would be unable to simulate this calculation even after a trillion trillion trillions years. The JT Quantum Computer leverages the entangled quantum interactions between the atoms, thusly mining the Hilbert Space of parallel universes and the multiverse in a manner that is at least several sextillion times faster than IBM's leading SUMMIT super computer.

And so the Joshua Tree Quantum Computer hath achieved quantum supremacy.

The Wright Brother's first flight lasted under a minute, and already we have crossed far further than that, with big plans for the future, and multitudinous commercial applications. A new era hath dawned.

We are currently seeking $200 million in funding to complete the design of the Redwood Quantum Computer, which will involve an entire bucket of water and which will be able to leverage the many worlds of Sean Carroll.

dx4/dt=ic friends, dx4/dt=ic :) :)