Qubit Count

There have been a lot of announcements recently regarding new chips or new simulators that contain a record number of qubits.   We thought it would be useful to our readers to compile all the information into one handy table that you can see below. Note that the data shown for the hardware items are for physical qubits without any error correction.

As we see more announcements in the coming months, you should remember that not all qubits are created equal.  A design that has qubits with long coherence times, high gate fidelities, and large connectivities may provide far better results than one that has many more qubits without these characteristics.  Unfortunately, these parameters are often not released publicly, so we are unable to publish them at this time.

The table below was compiled from publicly available sources as of November 2017.   Please let us know at info@quantumcomputingreport.com if you see any corrections that are needed or new entries to add.

Company Type Technology Now Next Goal
Intel Gate Superconducting 49 TBD
Google Gate Superconducting 72 TBD
IBM Gate Superconducting 50 TBD
Rigetti Gate Superconducting 19 TBD
USTC (China) Gate Superconducting 10 20
IonQ Gate Ion Trap 7 20-50
Silicon Quantum Computing Pty Gate Spin N/A 10
Univ. of Wisconsin Gate Neutral Atoms 49 TBD
Harvard/MIT Quantum Simulator Rydberg Atoms 51 TBD
Univ. of Maryland / NIST Quantum Simulator Ion Trap 53 TBD
D-Wave Annealing Superconducting 2048 5000
iARPA QEO Research Program Annealing Superconducting N/A 100
NTT/Univ. of Tokyo/Japan NII Qtm Neural Network Photonic 2048 100,000
Fujitsu Digital Annealer Classical 1024 100,000
IBM Research Software Simulator Classical 56 N/A
Microsoft – PC Software Simulator Classical 30 N/A
Microsoft – Azure Software Simulator Classical 40 N/A
Rigetti – Forest Software Simulator Classical 36 N/A
ETH Zurich Software Simulator Classical 45 N/A
Atos Software Simulator Classical 40 N/A

Updated January 14, 2018

Pierpaolo Malinverni
@ 2:16 am

All these qubits you list in your qubits count page are physical qubits but, to make a useful computation, we would need an additional number of qubits for error correction.
The number of error correction qubits is estimated to be in the range of 10^3 – 10^4 per physical qubit, which makes a big difference.
I would like to propose that you make clear that the qubits you mention in your page are physical qubits, and that at present no one has yet been able to make one logical qubit, the thing we need for computation.

    @ 11:47 am

    Thanks. I have added a sentence indicating that the hardware items reflect physical qubits. However, I would not agree that error correction is a hard requirement for all quantum computations. There are algorithms being researched such as VQE (Variable Quantum Eigensolver) and QAOA (Quantum Approximate Optimization Algorithm) that may be able to provide useful results on small quantum computers without error correction. A new term has been coined by Professor John Preskill for this called NISQ (Noisy Intermediate-Scale Quantum).

      Nqaba Ndlwana
      @ 4:28 am

      Hello Doug

      Just an enthusiast layperson who found your site yesterday. Just a suggestion for the scoreboards but could they be ordered, either ascending or descending, in order to more quickly and easily get a vague comparison. Include all caveats necessary though, as you did in the explanation.

        @ 9:45 am

        There actually is an order to the listing. First, the list is organized by Type and then by Technology. Notice in the Type column that all the Gates are together, all the Annealers are together, and all the Software Simulators are together. And in the Technology column all the Superconducting implementations are together as well as the Classical implementations. The reason for this is that it would not be correct to compare something like a software simulator to an annealer to a gate level hardware implementation because they are so much different.

          Nqaba Ndlwana
          @ 12:45 am

          Oh, I see. Thanks for pointing that out, as a layperson I just jump straight to the big numbers.

@ 7:54 am

thank you for creating this handy overview. It would be nice to have references (maybe via footnotes or links) for the listed numbers.

    @ 9:55 am

    Thank-you for your comment. It is a good idea and we will try to implement this as time permits. We have written a news article on almost all of these implementations. However we have not yet cross-referenced the article as shown on the News page to this list. If you do want to find the news article, we have a search feature on the web site. You can use the Search box at the very left bottom of each page to find the reference.


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