My Quantum Computing Wish List for Christmas 2021 and New Year 2022

  1. My top ten Christmas 2021 and New Year 2022 wishes
  2. A few additional wishes
  3. A special additional wish
  4. I know it’s Christmas, but enough with the toy algorithms
  5. My top five Christmas 2021 wishes?
  6. No, I’m not wishing for more qubits!
  7. But… we do need dramatic physical qubit growth to eventually support quantum error correction (QEC)
  8. I’d rather see better qubits for a smaller quantum computer
  9. Yes, I want to see more qubits, but not as the highest priority
  10. Yes, quantum error correction (QEC) is an urgent research priority but near-perfect qubits are a more-urgent near-term priority
  11. Quantum error correction (QEC) will no longer be high on my wish list until after we get near-perfect qubits
  12. Of course it will be interesting to see progress with Quantum Volume
  13. My non-wishes for Christmas 2021 and New Year 2022
  14. Variational methods are a technical dead-end and unlikely to ever achieve any significant quantum advantage
  15. My top Christmas 2021 wish
  16. Quantum Fourier transform (QFT) and quantum phase estimation (QPE) to support quantum parallelism are the Holy Grail for quantum computing
  17. My alternative top Christmas 2021 wish
  18. My other alternative top Christmas 2021 wish
  19. Some successes on my 2019 and 2020 wishes
  20. Some notable failures on my 2019 and 2020 wishes
  21. Still a mere laboratory curiosity of interest primarily to The Lunatic Fringe
  22. Still in pre-commercialization, still years from commercialization
  23. State of the art for quantum computing
  24. Changes to my wishes?

My top ten Christmas 2021 and New Year 2022 wishes

My top ten Christmas 2021 and New Year 2022 wishes, not in any strict order per se:

  1. Qubit fidelity of 3.5 nines. Approaching near-perfect qubits. I really want to see four nines (99.99%) within two years, but even IBM is saying that they won’t be able to deliver that until 2024. Trapped-ions may do better.
  2. Hardware capable of supporting quantum Fourier transform (QFT) and quantum phase estimation (QPE). Hopefully for at least 20 to 30 qubits, but even 16 or 12 or 10 or even 8 qubits would be better than nothing. Support for 40 to 50 if not 64 qubits would be my more ideal wish, but just feels way too impractical at this stage. QFT and QPE are the only viable path to quantum parallelism and ultimately to dramatic quantum advantage.
  3. Fine granularity of phase. Any improvement or even an attempt to characterize phase granularity at all. My real wish is for at least a million to a billion gradations — to support 20 to 30 qubits in a single QFT or QPE, but I’m not holding my breath for this in 2022.
  4. At least a handful of automatically scalable 40-qubit algorithms. And plenty of 32-qubit algorithms. Focused on simulation rather than real hardware since qubit quality is too low. Hopefully using quantum Fourier transform (QFT) and quantum phase estimation (QPE).
  5. Simulation of 44 qubits. I really want to see 48-qubit simulation — and plans for research for 50 and 54-qubit simulation. Including support for deeper circuits, not just raw qubit count. And configurability to closely match real and expected quantum hardware over the next few to five to seven years.
  6. At least a few programming model improvements. Or at least some research projects initiated.
  7. At least a handful of robust algorithmic building blocks. Which are applicable to the majority of quantum algorithms.
  8. At least one new qubit technology. At least one a year until we find one that really does the job.
  9. At least some notable progress on research for quantum error correction (QEC) and logical qubits. Possibly a roadmap for logical qubit capacity. When can we see even a single logical qubit and then two logical qubits, and then five logical qubits and then eight logical qubits?
  10. A strong uptick in research spending. More new programs and projects as well as more spending for existing programs and projects.

A few additional wishes

Some items that I really want but didn’t fit in the count:

  1. At least a paper proposal for an application to reach The ENIAC Moment.
  2. Greater transparency. What’s really going on under the hood of these quantum computers?! And why can’t the trapped-ion vendors be much more transparent?!
  3. Better documentation and specifications.
  4. Better roadmaps. More technical details and milestone metrics. See my critique of IBM’s quantum roadmap.
  5. Some fruit from Amazon’s research. More than just AWS hosting services for quantum computers from other vendors. An actual quantum computer.
  6. Trapped-ion vendors catch up with transmon vendors. I’d like to see 27 and 32-qubit trapped-ion quantum computers. And a clear and detailed roadmap for 40, 48, 50, 64, 72, 80, 96, and 128-qubit trapped-ion quantum computers. And transparency on qubit fidelity, fine granularity of phase, circuit depths, and gate execution times.
  7. Analytic tools to detect scalability problems for algorithms. Be able to detect coding patterns in algorithms which won’t scale to run on particular hardware configurations expected over the next few to five to seven years. Scaling for both up to 48 to 50 qubits and in the over-50 qubit range as well. Including circuit depth and coherence time. And this includes fine granularity of phase and probability amplitude to detect overly-ambitious use of quantum Fourier transform (QFT) and quantum phase estimation (QPE), and quantum amplitude estimation (QSE) as well.

A special additional wish

More a wish for me personally:

  1. I’d like to learn more about how quantum logic gates are implemented at the firmware and hardware level. Especially the actual physics. I’d like to understand theoretically how fine-grained rotations of phase angles and probability amplitudes can really be — how much is a theoretical limit vs. how much is just a limit of the current firmware, digital logic, and analog control logic. My motivation is to understand the implementation and limitations of quantum Fourier transform (QFT) and quantum phase estimation (QPE) in support of quantum computational chemistry and other applications for QFT and QPE.

I know it’s Christmas, but enough with the toy algorithms

Very small algorithms can be illustrious for beginners, but the field is plagued by tiny algorithms. I don’t care what you can do with five or seven or even eleven qubits. If your algorithm isn’t using at least 24 qubits, then I don’t want to hear about it. Okay, maybe that’s a bit extreme, but at least 20 qubits or maybe 16 qubits at a minimum. I’m at least comfortable saying that anything less than a 16-qubit quantum algorithm is definitely a toy algorithm.

My top five Christmas 2021 wishes?

I really tried to whittle my wish list down from ten to five, but I really can’t. You can pick any five of my top ten at random, but I can’t do any better than that.

No, I’m not wishing for more qubits!

Sure, a 256-qubit quantum computer, or 160 qubits, would be great, but the simple fact is that we have reached the point where raw qubit count is not the limiting factor. The main limiting factors are:

  1. Qubit fidelity. Really need four nines to do anything substantial.
  2. Coherence time and circuit depth. Too short to do much of value.
  3. Gate fidelity. Gate error rate is still too high.
  4. Measurement fidelity. Qubit results mean nothing if you can’t accurately measure them.
  5. Connectivity. Full any to any connectivity is needed. Or at least something much closer than nearest neighbor.
  6. Automatically scalable 40-qubit algorithms. See we need even larger and more complex algorithms, but we can’t even muster 40 qubits at this time.

But… we do need dramatic physical qubit growth to eventually support quantum error correction (QEC)

Although additional noisy qubits aren’t helpful to algorithm designers and application developers, we do need to eventually get to much larger numbers of physical qubits, even if still somewhat noisy, to support quantum error correction (QEC) and logical qubits.

I’d rather see better qubits for a smaller quantum computer

Rather than larger qubit counts, such as more 100-qubit machines and even a 256-qubit machine, I’d rather see a 48-qubit machine with better qubits. And even refinements for 28 and 32-qubit machines.

Yes, I want to see more qubits, but not as the highest priority

Eventually we will indeed need 256 and 1,000-qubit machines, and even 4K-qubit machines, but until qubit quality permits larger and more complex quantum algorithms, those higher qubit counts will not be used effectively.

Yes, quantum error correction (QEC) is an urgent research priority but near-perfect qubits are a more-urgent near-term priority

Quantum error correction (QEC) is still years away. Yes, research is needed and I expect progress in research over the coming year, but I expect nothing to put in the hands of users for another couple of years. Quantum algorithms need significant near-term improvements in qubit quality, so I would give near-perfect qubits a higher near-term priority.

Quantum error correction (QEC) will no longer be high on my wish list until after we get near-perfect qubits

Progress on quantum error correction (QEC) and logical qubits, also known as fault-tolerant quantum computing, was previously high on my Christmas wish lists, and yes, quantum error correction (QEC) must remain a high research priority, but as a longer-term goal, without usable results in the next couple of years. It won’t be high on my wish list until after we have near-perfect qubits available, such as four nines of 40 qubits.

Of course it will be interesting to see progress with Quantum Volume

It’s kind of a slam dunk for IBM to achieve a Quantum Volume (QV) of 256 in 2022 — they’re at 128 now. I would hope they could easily hit 512 (9 qubits). Maybe even 1K (10 qubits). But 2K or 4K or higher are probably out of reach this coming year, or maybe even the following year.

My non-wishes for Christmas 2021 and New Year 2022

Just to recap, here are perfectly reasonable achievements which quantum computing could make in the coming year, but they simply aren’t in my personal top ten priorities at this time:

  1. More qubits.
  2. Progress in Quantum Volume (QV). Not a particularly helpful metric at this stage. The focus should be on enhancing qubit quality and qubit-specific metrics such as nines of qubit fidelity and connectivity.
  3. Progress on quantum error correction (QEC) and logical qubits. Research, yes, but nothing to put in the hands of users for a few more years.
  4. More hardware vendors. Nominally I do still want to see more hardware vendors, but I want to see more hardware progress from the existing hardware vendors first as the higher priority.

Variational methods are a technical dead-end and unlikely to ever achieve any significant quantum advantage

Although variational methods are quite popular, they are unlikely to ever achieve any significant quantum advantage. Without a significant quantum advantage, they are a technical dead-end.

My top Christmas 2021 wish

If I could have only one wish, what would it be? I’d wish for…

  1. Hardware capable of supporting quantum Fourier transform (QFT) and quantum phase estimation (QPE). Hopefully for at least 20 to 30 qubits, but even 16 or 12 or 10 or even 8 qubits would be better than nothing. Support for 40 to 50 if not 64 qubits would be my more ideal wish, but just feels way too impractical at this stage. QFT and QPE are the only viable path to quantum parallelism and ultimately to dramatic quantum advantage.
  1. Qubit fidelity. Low error rate.
  2. Qubit connectivity. Much better than only nearest neighbor. Sorry, SWAP networks don’t cut it.
  3. Gate fidelity. Low error rate. Especially 2-qubit gates.
  4. Measurement fidelity. Low error rate.
  5. Coherence time and circuit depth. Can’t do much with current hardware.
  6. Fine granularity of phase. At least a million to a billion gradations — to support 20 to 30 qubits in a single QFT or QPE.

Quantum Fourier transform (QFT) and quantum phase estimation (QPE) to support quantum parallelism are the Holy Grail for quantum computing

So far, quantum Fourier transform (QFT) and quantum phase estimation (QPE) are the best known technical approach to achieving quantum parallelism. That makes them the Holy Grail of quantum computing. QFT and QPE are the only viable path to quantum parallelism and ultimately to dramatic quantum advantage.

My alternative top Christmas 2021 wish

Since my top wish may seem more like a cheat since I’m supposed to be asking for only one wish, I’d replace that wish with:

  1. Fine granularity of phase. At least a million to a billion gradations — to support 20 to 30 qubits in a single QFT or QPE.

My other alternative top Christmas 2021 wish

And if even that seems like too much of a cheat, I’d wish for simply:

  1. Qubit fidelity of 3.5 nines. Approaching near-perfect qubits. I really want to see four nines (99.99%) within two years, but even IBM is saying that they won’t be able to deliver that until 2024. Trapped-ions may do better.

Some successes on my 2019 and 2020 wishes

Although most of my wishes from prior years have not been granted, there have been a few successes:

  1. 100+ qubits. At least one machine in the 100+ qubit range. IBM just announced the 127-qubit Eagle. Another 100+ machine, Atom Computing Phoenix, has been “unveiled”, but its actual availability is unclear. And another, ColdQuanta Hilbert, is expected early in 2022.
  2. Additional hardware vendors. More than a few have popped up.
  3. Another qubit technology. Two vendors of neutral atom qubits have surfaced.
  4. Much more fundamental R&D. A palpable increase and announcement of new programs and projects. Not as much as I wanted, but some progress.
  5. Honeywell has made notable progress with QV of 1024. That at least demonstrates that trapped-ion qubits have superior connectivity compared to superconducting transmon qubits.

Some notable failures on my 2019 and 2020 wishes

  1. No quantum computer from Microsoft.
  2. No quantum computer from Intel.
  3. No new quantum computer from Google.
  4. Rigetti still hasn’t gotten past 32 qubits.
  5. IonQ hasn’t gotten past 32 qubits.
  6. Xanadu is still far from a practical photonic quantum computer. Great promise, but we’re trying to move past mere promises.
  7. Haven’t gotten to three nines of qubit fidelity. IBM did announce something recently, but it was “best” case, not nominal case.
  8. No improvement in qubit connectivity. For superconducting transmon qubits. Trapped-ion qubits seem all set.
  9. Simulators haven’t gotten past 32 or 40 qubits.
  10. People are still touting Grover search and Shor’s factoring algorithm. Time to move on! Focus on practical algorithms for the three to five year horizon.
  11. Limited transparency.
  12. Mediocre documentation.
  13. Mediocre roadmaps.
  14. No apparent progress on fine granularity of phase or quantum Fourier transform (QFT) or quantum phase estimation (QPE).

Still a mere laboratory curiosity of interest primarily to The Lunatic Fringe

I know people are working really hard and great progress is being made, but even with all of my Christmas and New Year wishes, quantum computing will still remain a mere laboratory curiosity of interest primarily to The Lunatic Fringe — who will work with any technology no matter how limited or how far from completion it is — even as 2022 ends and 2023 begins.

Still in pre-commercialization, still years from commercialization

Much research, prototyping, and experimentation is still required until we have sufficient technical knowledge and capabilities to even begin commercialization of quantum computing, which itself will take years.

State of the art for quantum computing

My list of wishes can also be read as a summary of the state of the art for quantum computing — not so much how much has been done, but how much work remains until quantum computing will be ready for development and deployment of production-scale practical real-world applications which can routinely achieve dramatic quantum advantage.

Changes to my wishes?

I reserve the right to make changes to my wishes right up until 11:59 PM on December 24, 2021 — Christmas Eve. And I expect Santa’s elves to be responsive to such late-breaking requests!

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