9

A serious answer: you pretty much can't. It's not that you in particular can't, it's that no one can. Huge companies pour in huge amounts of money to try and make a proof-of-concept quantum computer (there is actually no 'proper' quantum computer yet). A slightly less serious answer: some odd $10-100$ Million would get you started I would say. It all depends ...


8

They have different error rates because they are two different physical devices! This relates to the manufacturing processes of these chips. Every device is unique and will have its own fingerprint meaning its own error rate. Of course this is not something that manufactures do on purpose, but a side effect of making these qubit devices. It’s very difficult ...


7

With current technology, there's not much of a chance to build a true quantum computer, but you may be able to build some interesting quantum circuits with a fairly sizable (but still on the scale of "self-funded" for the ordinary person) budget, using the optical photon model. For instance, one could use the linear optical quantum computing model. Using ...


6

Note that while you probably can't build a quantum computer at home, you can simulate one with a classical computer, at the cost of merely an exponential slowdown. There's a rather long list of available software at https://www.quantiki.org/wiki/list-qc-simulators.


4

All of the backends are bidirectional from the viewpoint of Qiskit. The Cross-Resonance (CR) gate used in implementing the CNOT has a natural preferred direction associated with it, but accounting for the direction is done automatically by the devices, thus yielding a bi-directional topology.


3

Although it doesn't explicitly say it in the paper from Google, the diagrams in the paper are missing a qubit along the top edge. Most likely this is the "bad" qubit that wasn't used.


3

When I visited the Google Hardware Lab, they were extremely secretive about everything. It is unlikely anyone will be able to answer this question except for the narrow range of Google Hardware Lab employees, and the ones I know are not very open about what Google is doing. What I can do is answer what a different superconducting-qubit hardware company (D-...


3

By coincidence, this article just came out on Ars Technica which might answer some of your questions. (This is not an endorsement of everything written in that article. But the author basically asked, and researched, the same question that you're asking.) The TL;DR answer is that superconducting qubits are manufactured and allow for better control over ...


3

The question is fine, but I think still a bit difficult to answer in a non-subjective way. A cursory exploration on google will provide you with examples of papers proposing computing paradigms based on things such as effects of general relativity (gravitational waves) or string theory, and probably other similar examples. I am not qualified enough in ...


3

It's actually an interesting question. And the previous answers ("strictly speaking, you can't," "you can simulate quantum computers," and "photonics-based processing holds some promise") are all true. According to a pioneer in photonics computing we won't see real quantum computing until around 2035. I've not yet seen anything to justify thinking to the ...


2

Extension of Anin Post above (I havent been able to login back into that account, so set up a new one) Limits of the Quantum Biology as Biological Semiconductor Approach Quantum biology cannot simply solve the practical concerns of quantum computing as they stand - as biology is not simply a form of semiconductor or quantum computer. I note that ...


2

According to comment provided by user gIS, there was no progress in implementing qRAM as proposed in the paper. However, some additional information on qRAM physical implementation can be found on this forum here.


2

I would add that thermic noise, radiocative background (mainly cosmic rays) can play role in different error rate as those noise sources are different for each quantum processor. Moreover, as a user of IBM Q, you probably know that quantum processors are sometimes under maintenance. Since each processor is maintained in different time, their runtime is ...


1

Space-based cryogenic cost must become cheaper than Earth-based cryogenic cost and cheaper than classical computation emulating quantum computation. Earth application IO datalink and general space operations cost must fall as well. Mass space colonization will help.


1

I know this isn't really what you're thinking of with your question, but measurement-based quantum computing is pretty well studied. Under the many-worlds interpretation, the system counts as open for that protocol, because every time you perform a measurement you're becoming entangled with the system.


1

Quantum computers are susceptible to these errors/noise because of physical disturbances. An example of this is if some molecule in the surrounding air were to bump or approach the qubit it would transfer some kinetic energy and maybe affect the state. Another example is if a qubit interferes with any adjacent qubit, if they "bump" into one another their ...


1

How is D-Wave's Pegasus architecture different from the Chimera architecture? See: "Pegasus: The second connectivity graph for large-scale quantum annealing hardware" (Jan 22 2019), by Nike Dattani (Harvard), Szilard Szalay (Wigner Research Centre), and Nick Chancellor (Durham). Figures were made with their open source software PegasusDraw. "The 128 ...


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