Cloud-Based Quantum Computing Is Almost Ready For Business

Thus sayeth Rigetti:

From Fast Company, September 7:

In launching its own online service, the Berkeley-based upstart Rigetti aspires to be the Amazon of cloud-based quantum computing. 

Quantum computing–which harnesses the peculiar physics of subatomic scale–long appeared to be a technology of the far future, maybe decades away. But the sci-fi tech is coming to market way sooner than was expected just a few years ago, due to new thinking on how to make use of its still-imperfect capabilities. Along with behemoths like Google and IBM, Berkeley-based company Rigetti is making a bid to grab the market. And it may—at the moment at least—be in the lead.

Today the startup launches a project in the mold of Amazon Web Services (AWS) called Quantum Cloud Services. “What this platform achieves for the very first time is an integrated computing system that is the first quantum cloud services architecture,” says Chad Rigetti, founder and CEO of his namesake company. The dozen initial users Rigetti has announced include biotech and chemistry companies harnessing quantum technology to study complex molecules in order to develop new drugs.

I met the physicist earlier this week to see what a quantum data center looks like. Next to each of several fat white cylinders holding the super-cooled quantum computers are racks of traditional servers–constituting the quantum-classical hybrid systems that are bringing this bizarre physics to market.

The particular operations that the quantum end of the system can do, while still limited and error-prone, are nearly good enough to boost the performance of traditional computers beyond what they could do on their own–a coming milestone called quantum advantage. “My guess is this could happen anytime from six to 36 months out,” says Rigetti.

o-called hybrid algorithms leveraging both systems are able to spot and correct some errors. And even imperfect results from quantum computers can be good enough in many cases, either flat-out exceeding what traditional computer technology can do, or producing results faster or cheaper.

Rigetti has been playing this angle, creating a software development kit called Forest (because it’s an ecosystem, says Chad) that allows programmers to access hybrid systems. Like other companies such as IBM, Rigetti has been allowing developers to access small-scale quantum computers online to essentially start working out how to program for them. The company learned a lot since opening this up in December 2017, says Rigetti. For instance, it originally tried providing just the quantum end of the system from its own data centers, linking it to traditional computers running on AWS. But the lag time between the systems, though minimal, was long enough to limit performance.

Hence the decision to provide all the computing in its own Berkeley data center. Rigetti is now inviting customers to apply for free access to these systems, toward the goal of developing a real-world application that achieves quantum advantage. As an extra incentive, the first to make it wins a $1 million prize. “What we want to do is focus on the commercial utility and applicability of these machines, because ultimately that’s why this company exists,” says Rigetti. (On that promise, the company has raised $119.5 million from investors, including Andreessen Horowitz.)...

...MUCH MORE

Previously:
April 2017 
Quantum Computing Startup Rigetti Computing Raises $64 Million in Funding
February 2018 
You Think the Have/Have-not Divide Is Big Now? Just Wait Until AI has a Quantum Computer Brain

Quantum Computing Startup Rigetti Computing Raises $64 Million in Funding

The other day I mentioned that D-Wave wasn't yet a "real" quantum computer but that they were closer than anyone currently in production. Here's one of the up-and-comers.
From Inside HPC, March 29:

Today Rigetti Computing, a leading quantum computing start-up, announced it has raised $64 million in Series A and B funding.

Quantum computing will enable people to tackle a whole new set of problems that were previously unsolvable,” said Chad Rigetti, founder and chief executive officer of Rigetti Computing. “This is the next generation of advanced computing technology. The potential to make a positive impact on humanity is enormous.”

The Series A round of $24 million was led by Andreessen Horowitz. Vijay Pande, general partner at Andreessen Horowitz, has been appointed to Rigetti’s Board of Directors, joining Rigetti CEO Chad Rigetti and angel investor Charlie Songhurst. The Series B round of $40 million was led by Vy Capital, followed by Andreessen Horowitz.

Rigetti Computing was founded by Chad Rigetti in 2013 and has offices in Fremont and Berkeley, Calif. The company is building a cloud quantum computing platform for artificial intelligence and computational chemistry. Rigetti recently opened up private beta testing of Forest, its API for quantum computing in the cloud. Forest emphasizes a quantum-classical hybrid computing model, integrating directly with existing cloud infrastructure and treating the quantum computer as an accelerator.

Quantum computers store and process information using individual photons, enabling dramatically greater computational power and energy efficiency. Rigetti Computing has taken a highly interdisciplinary approach to developing the technology, with a team from diverse backgrounds in computer science, engineering, physics, and chemistry....

...MORE

You Think the Have/Have-not Divide Is Big Now? Just Wait Until AI has a Quantum Computer Brain

Following up on the post immediately below, "How Amazon Rebuilt Itself Around Artificial Intelligence".
From MIT's Technology Review, December 18, 2017:

If it fulfills its promise, quantum machine learning could transform AI.

A company in California just proved that an exotic and potentially game-changing kind of computer can be used to perform a common form of machine learning.

The feat raises hopes that quantum computers, which exploit the logic-defying principles of quantum physics to perform certain types of calculations at ridiculous speeds, could have a big impact on the hottest area of the tech industry: artificial intelligence.

Researchers at Rigetti Computing, a company based in Berkeley, California, used one of its prototype quantum chips—a superconducting device housed within an elaborate super-chilled setup—to run what’s known as a clustering algorithm. Clustering is a machine-learning technique used to organize data into similar groups. Rigetti is also making the new quantum computer—which can handle 19 quantum bits, or qubits—available through its cloud computing platform, called Forest, today.

The demonstration does not, however, mean quantum computers are poised to revolutionize AI. Quantum computers are so exotic that no one quite knows what the killer apps might be. Rigetti’s algorithm, for instance, isn’t of any practical use, and it isn’t entirely clear how useful it would be to perform clustering tasks on a quantum machine.

Still, Will Zeng, head of software and applications at Rigetti, argues that the work represents a key step toward building a quantum machine. “This is a new path toward practical applications for quantum computers,” Zeng says. “Clustering is a really fundamental and foundational mathematical problem. No one has ever shown you can do this.”

There is currently a remarkable amount of excitement surrounding efforts to develop practical quantum computers. Big technology companies, including IBM, Google, Intel, and Microsoft, as well as a few well-funded startups are racing to build exotic machines that promise to usher in a fundamentally new form of computing.

First dreamed up by physicists almost 40 years ago, quantum computers do not handle information using binary 1s and 0s. Instead, they exploit two quantum phenomena—superposition and entanglement—to perform calculations on large quantities of data at once. The nature of quantum physics means that a computer with just 100 qubits should be capable of calculations on a mind-boggling scale.

Rigetti is something of an underdog in the race. IBM recently announced that it has built a quantum computer with 50 qubits, and Google is widely rumored to have a device of similar scale. Still, Rigetti has plenty of boosters. The company has raised around $70 million from investors including Andreessen Horowitz, one of Silicon Valley’s most prominent firms.

Having more qubits doesn’t necessarily equate to superiority, though. Maintaining quantum states and manipulating qubits reliably represent formidable challenges.

Like some others, Rigetti uses a hybrid approach, meaning its quantum machine works in concert with a conventional one to make programming more straightforward. Zeng says the company’s systems are also more modular than its rivals’, which may offer a significant edge when it comes to scaling machines up further.

Quantum computing has tremendous potential, in theory. There is good evidence that quantum machines can be used to solve cryptographic challenges and to simulate new material. And there is hope that algorithms such Rigetti’s will eventually transform the world of machine learning and AI....

...MUCH MORE

Previously:

April 2017
Quantum Computing Startup Rigetti Computing Raises $64 Million in Funding
The other day I mentioned that D-Wave wasn't yet a "real" quantum computer but that they were closer than anyone currently in production. Here's one of the up-and-comers....

Losses continue for quantum computer companies, trending slowly in the right direction

 From DatacenterDynamics, August 23:

Quantum computing earnings Q2 2024: IonQ, Rigetti, D-Wave results

Quantum computing firms IonQ, Rigetti, and D-Wave have announced their Q2 2024 earnings results.

All three companies continued to post losses as they seek to build systems capable of surpassing classical supercomputers, though some saw those losses narrow slightly.

IonQ: Revenue up, net losses down, another govt contract win
For Q2 2024, IonQ reported $11.4 million in revenue; up 106 percent on Q2 2023’s $5.5 million.

Net loss for the quarter was $37.6 million and adjusted EBITDA (earnings before interest, taxes, depreciation, and amortization) loss was $23.7m; Q2 2023 saw a net loss of $43.7m and adjusted EBITDA loss of $19.4m.

During Q1 2024, IonQ recognized revenue of $7.6 million for the first quarter, compared to $4.3 million in the prior year. Net loss was $39.6 million and adjusted EBITDA loss was $27 million.

“This was a tremendous quarter for IonQ, with the company posting revenue well above the high-end of our guidance range and leading the industry in technical innovations that have brought the quantum era within reach,” said Peter Chapman, president and CEO of IonQ.

“Specifically, the second quarter saw the launch of our accelerated technical roadmap, our demonstration of 99.9 percent fidelity using our next-generation barium qubits, and our invention of an industry-first partial error correction scheme, a new technique that could allow much larger applications to run on near-term quantum systems.”

The company secured $9 million in new bookings for the second quarter. The company announced it was to supply the Applied Research Laboratory for Intelligence and Security (ARLIS) with a networked system for ‘blind’ quantum computing, where the system remains ‘blind’ to what information is being processed through them.

The initial phase of the $40m contract is a $5.7 million award for the design of the quantum computers based on IonQ trapped ion processors, due for completion by the end of the year. ARLIS plans to have two systems built based on the initial IonQ design.

IonQ said it also extended its contract with Amazon Web Services (AWS) to continue to offer its quantum computers via Amazon’s quantum service, Braket.

For Q2 2024, total operating costs and expenses for the second quarter were $60.3 million, up 56 percent from $38.6 million in the prior year period, but within the company's plan.

Rigetti: Revenue flat, losses drop slightly
Rigetti posted Q2 revenue of $3.1 million. Operating loss for the quarter was $16.1 million, while the net loss was $12.4 million. This compaed to revenue of $3.3 million and a net loss of $17m in the same period 12 months ago....

....MUCH MORE

Nvidia GTC: The Company Holds It's First Quantum Day, "Quantum Stocks" Down 9% to 19% (NVDA; IONQ; QBTS: RGTI)

First up (all links March 20), mainly because I like their headline, Investor's Business Daily:

Nvidia Chief Hosts Quantum Computing Execs After Dis 

• 01:29 PM ET 03/20/2025

Two months ago at the CES conference, Nvidia (NVDA) Chief Executive Jensen Huang dismissed quantum computing as something that won't be very useful for 15 to 30 years. But on Thursday Huang hosted a roundtable discussion on the technology at the Nvidia GTC conference in San Jose, Calif.

The event called Quantum Day was a mea culpa of sorts for Huang to a nascent industry that holds great promise.

At Quantum Day, Huang said the idea for the panel came about after his dismissive comments at CES. He invited quantum computing executives to GTC "to explain why he was wrong."

Quantum computing has tremendous potential but is "insanely complicated," Huang said.

The roundtable discussion included executives from such quantum computing companies as D-Wave Quantum (QBTS), IonQ (IONQ) and Rigetti Computing (RGTI).

Other companies represented at Quantum Day were Alice & Bob, Atom Computing, Infleqtion, Pasqal, PsiQuantum, Quantinuum, Quantum Circuits, QuEra Computing and SEEQC.

Microsoft (MSFT) and Amazon.com (AMZN) unit AWS also participated in the chat.

On Jan. 7, during a question-and-answer session with financial analysts at CES, Huang said quantum computing will be useful for "small data, big compute, big combinatorial computing problems." That includes applications such as cryptography. "It's not good at large data problems."

He said 15 years probably would be "on the early side … for very useful quantum computers."

Nevertheless, Nvidia is working with quantum computing companies to advance the technology, Huang said.

"We want to help the industry get there as fast as possible and to create the computer of the future and we'll be a very significant part of it," Huang said at the CES event.

On Tuesday, Nvidia announced that it is building a Boston-based research center to advance quantum computing....

....MORE

And from Bloomberg via India's Mint:

Nvidia CEO Says He Was Surprised That Publicly Held Quantum Firms Exist 

Nvidia Corp. Chief Executive Officer Jensen Huang said he didn’t realize there were publicly traded quantum-computing companies when he made earlier comments that caused industry stocks to crash.

Nvidia Corp. Chief Executive Officer Jensen Huang said he didn’t realize there were publicly traded quantum-computing companies when he made earlier comments that caused industry stocks to crash.

“My first reaction was, I didn’t know they were public. How can a quantum company be public?” Huang said at an event Thursday focused on the still-nascent technology....

....MORE

As the quantum guys on the stage are thinking: "NOT HELPING"

And from Barron's, who are almost live-blooging the event (multiple posts, multiple by-lines):

What Does the Future Hold for Quantum Computing?

As the first panel at Nvidia GTC’s inaugural Quantum Day came to a close, Nvidia CEO Jensen Huang asked the participants a burning question--what they would be discussing at next year’s event.

Each panelist provided an answer that alluded to a different vision for quantum computing. D-Wave Quantum CEO Alan Baratz pointed to the use of quantum to better train artificial intelligence models, while IonQ CEO Peter Chapman cited quantum’s applications in managing customer workloads.

What Does the Future Hold for Quantum Computing?

Mackenzie Tatananni

Updated 2025-03-20 18:43 ET / Original 2025-03-20 18:22 ET

As the first panel at Nvidia GTC’s inaugural Quantum Day came to a close, Nvidia CEO Jensen Huang asked the participants a burning question--what they would be discussing at next year’s event.

Each panelist provided an answer that alluded to a different vision for quantum computing. D-Wave Quantum CEO Alan Baratz pointed to the use of quantum to better train artificial intelligence models, while IonQ CEO Peter Chapman cited quantum’s applications in managing customer workloads.

Loïc Henriet, CEO of Pasqal, said he was excited to discuss the real-world use cases of computers that had already been deployed.

Quantinuum CEO Rajeeb Hazra agreed with the previous speakers before giving an answer that alluded to his company’s work with Nvidia at its Accelerated Quantum Research Center, which is set to begin operations later this year.

“We will see, in the next year, the first real tangible use cases of an AI agent working in conjunction with a quantum computer, doing things it otherwise couldn’t have done before,” Hazra said.

Rigetti CEO Subodh Kulkarni expressed eagerness for the skepticism around quantum technology to dissolve and be replaced by discussions of its applications in data centers....

....MORE

Also st  Barron's:

Huang Apologizes to Attendees in Quantum Day Remarks

Quantum Stocks Fall as Nvidia Quantum Day Gears Up

Jensen Huang Kicks Off Quantum Event 

And the complete package, about 20 minutes ago:

Nvidia Quantum Day: D-Wave, IonQ, Rigetti Stocks Tumble During Event With Jensen Huang
Follow live coverage of quantum industry leaders and Nvidia CEO Jensen Huang as they discuss the future of quantum computing from Nvidia's GTC conference. 

Recently:

March 7 -  "As NVIDIA’s Quantum Day Nears, Analysts Suggest Event is More Than a Gesture" (NVDA)

You know what looks cheap? Nvidia looks cheap.

That's not to say it can't get cheaper but to quote some of the old-time traders: "Well bought is half sold."

$111.29 last, up $0.72 (+0.65%) in late pre-market trading.

And the outro:

Although we see no rush to own the current batch of publicly traded names, we do pay attention to what the chatter is. Some of our previous links and more recent comments were wrapped in January 8's "Quantum Stocks Drop as Nvidia CEO Sees Use Years Away":

Ditto and double ditto for the quantum computing stocks. There will be at least one and possibly three bear markets before they are even close to earning money.

However, for the diehard next-big-thing wannabes we did link to Barron's "...How to Pretend You Understand Quantum Computing." on Dec 14.

Here's Nvidia:

NVIDIA GTC 2025: Quantum Day to Illuminate the Future of Quantum Computing

NVIDIA CEO Jensen Huang and Industry Visionaries to Unveil What’s Next in AI at GTC 2025

Quantum Day Conference Sessions

Previously:

This is Goofy: "Quantum-computing stocks are soaring as investors place bets on ‘the next big thing’ in tech"

Our general rules for shorting: In a bull market only short frauds, and even then be aware that what you think you are seeing may take quite a while to become evident to the wider market. Or may prove to have been an hallucination on the part of the prospective short seller.

In a bear market you can expand your shortable universe by also using shorts based on valuation.

Here are three names to keep in mind as valuation shorts should the overall market begin to crack sometime in the next year or two. From MarketWatch, December 11....

*****

We happened to catch the Google story via the NYT on Monday evening: "Quantum Computing Inches Closer to Reality After Another Google Breakthrough" (GOOG).

The next trading day it was up ~5%. Today it set a new all-time-high.

If interested we have quite a few posts on D-Wave and to a lesser extent Rigetti. Use the 'search blog' box upper left. 

One final word on risk. If an overvalued company you are short actually has some worthwhile technology there is a real risk that they might be acquired for that technology, which can wreck your whole day.

Or more importantly your annual bonus.

Quantum Stocks Drop as Nvidia CEO Sees Use Years Away
Could not agree more.*....

"Nvidia’s Jensen Huang is ‘dead wrong’ about quantum computers, D-Wave CEO says" (QBTS; RGTI; IONQ)

Not exactly a Quantum of Solace for speculators down 35 - 45% yesterday but then D-Wave's CEO is no Daniel Craig:

On the other hand Mr. Craig isn't an MIT-trained computer science PhD and former Warburg Pincus MD where he crossed paths with Bill Janeway.

 And hundreds more including a 2019 post that might induce Déjà vu:

"Quantum gold rush: the private funding pouring into quantum start-ups"

Betting on Quantum Computing

Not a lot of pure plays, and I can't think of any that are publicly traded.

From PitchBook:

Investors bet on the technologically unproven field of quantum computing

Scientists and engineers are still toiling in labs in a race to develop quantum computers that would significantly outperform traditional computers.

But that isn't holding venture capitalists back. They're pouring record-high funding into work on computing power that is still considered years away from being ready.

Investors have invested $1.02 billion into quantum computing companies so far this year. That's more than was funneled into the industry during the previous three years combined, according to PitchBook data.

*****

Notable recent quantum computing deals

Deal Date

Deal Size (millions)

Post-money Valuation (millions)

Select Investors

Company HQ
PsiQuantum	7/27/2021	$450.0	$3,150.0	Baillie Gifford, BlackRock, M12, Temasek	Palo Alto
Xanadu	5/25/2021	$100.0	N/A	Bessemer Venture Partners, Georgian, Tiger Global	Toronto
Rigetti	8/4/2020	$79.0	N/A	Andreessen Horowitz, Battery Ventures, Bessemer Venture Partners, DCVC	Berkeley, Calif.
IonQ	6/16/2020	$62.0	$192.0	Airbus Ventures, Amazon Web Services, Mubadala	College Park, Md.
Quantum Machines	9/6/2021	$50.0	N/A	Battery Ventures, Red Dot Capital Partners, Samsung NEXT Ventures, Valor Equity Partners	Tel Aviv

Data as of Sept. 8, 2021

.....MUCH MORE

We have quite a few posts on quantum computing, for the longest time I didn't believe that D-Wave actually had what they said they had.

Here are a few of our posts that mention Rigetti, one name that may turn into something:

• The Market for Quantum Technology: Early Revenue-Generating Applications
• "Quantum gold rush: the private funding pouring into quantum start-ups"

That second link has quite a few prior posts with the headline story from the journal Nature, who had a couple other articles that may be of interest:

Also at Nature, Oct. 2:
Beyond quantum supremacy: the hunt for useful quantum computers

Way back in 2017 Nature was posting (and we were linking): "Google's Quantum AI Laboratory set out investment opportunities on the road to the ultimate quantum machines" (GOOG).

For more names we have on offer 2018's
"10 Quantum Computing Startups Getting Funded in 2018"
Keeping in mind that Google is pretty fired up on D-Wave's architecture while Rigetti and Alibaba are developing proprietary systems.

And MIT's Technology Review:
You Think the Have/Have-not Divide Is Big Now? Just Wait Until AI has a Quantum Computer Brain

So, if interested those are a starting point. Otherwise, you know the drill, use the 'search blog' box upper left.

So, Where Are We At With The Pure Plays? "Quantum computing Q4 2023 results: IonQ, Rigetti, D-Wave"

Question mark in headline? Betteridge's law doesn't apply to queries with non-binary answers,

From Data Center Dynamics, April 3:

Revenues up, losses up for quantum companies

Quantum computing companies IonQ, Rigetti, and D-Wave have posted their Q4 2023 quarterly results, as well as their end-of-year results.

All three companies posted increased revenues, but continue to see losses. All three say commercially useful quantum computers are a few years away but promise to open a market with tens, if not hundreds, of billions of dollars.

IonQ: co-founder and CTO Kim to return to academia
Q4 2023 saw IonQ post $6.1 million in revenue. Quarterly net loss was $41.9 million and Adjusted EBITDA (earnings before interest, taxes, depreciation, and amortization) loss was $20m.

For the whole year, IonQ posted $22 million in revenue. Across 2023 as a whole, net loss was $157.8 million and Adjusted EBITDA loss was $77.7 million.

“IonQ had a landmark year in 2023, meeting and exceeding our financial expectations, and accomplishing our technical goals early,” said Peter Chapman, President and CEO of IonQ. “We sold four systems, unveiled the designs for our upcoming generations, and opened our new Seattle manufacturing facility to begin producing more systems to fulfill our growing pipeline. IonQ’s pipeline for 2024 is stronger than ever, and our sale of two systems in Europe last year is accelerating interest in system purchases, especially in Europe.”

The company secured $6.7 million in new bookings for the fourth quarter and $65.1 million for the full year. The company didn’t book any hardware sales in Q4.

For the full year 2024, IonQ expects revenue to be between $37 million and $41m; bookings are expected to be between $70 million and $90m.

During the quarter, the company said it had demonstrated its forthcoming photonic integrated circuit, or PIC, technology in a lab setting. This technology will allow for the light that controls qubits to be routed directly to QPUs. The company said this means it can reduce reliance on lenses and mirrors within the computers.

Work on the company’s first production-class IonQ Forte Enterprise systems has started in its new Seattle manufacturing facility, with plans to begin delivery to customers by the end of 2024.

The company also said it achieved algorithmic qubits (#AQ) 36 on IonQ Forte, which CEO Peter Chapman said ‘effectively doubled the computational space’ of the system.

IonQ co-founder and CTO, Jungsang Kim, is to leave his position to focus on his academic duties at Duke University. He will continue to advise IonQ as a scientific adviser.

Rigetti: Company to deliver a QPU to the UK's National Quantum Computing Centre...

....MUCH MORE

Google and the rest of the behemoths don't break out revenues and losses for their quantum 'puter efforts.

This is Goofy: "Quantum-computing stocks are soaring as investors place bets on ‘the next big thing’ in tech"

Our general rules for shorting: In a bull market only short frauds, and even then be aware that what you think you are seeing may take quite a while to become evident to the wider market. Or may prove to have been an hallucination on the part of the prospective short seller.

In a bear market you can expand your shortable universe by also using shorts based on valuation.

Here are three names to keep in mind as valuation shorts should the overall market begin to crack sometime in the next year or two. From MarketWatch, December 11:

 Shares of three tiny companies have seen enormous gains over the past few months

A trio of quantum-computing stocks has seen huge gains over the past few months, bolstered by a wave of hype from retail investors looking to cash in on what could be the “next big thing” in tech.

Shares of Rigetti Computing Inc, D-Wave Quantum Inc. and IonQ Inc. — all small-capitalization stocks closely associated with quantum computing —have gained 843%, 455% and 398% in the three months through Tuesday’s close, FactSet data showed.

The Defiance Quantum ETF — which invests in a number of mature and developing companies involved in quantum computing and machine learning — has gained more than 30% over the same period.

For shareholders of these companies, the gains amount to only a few billion dollars’ worth of value creation. Still, a steady drumbeat of new developments, coupled with their strong performance in the market, appears to have piqued investors’ interest.

The latest market-moving announcement landed shortly before the closing bell on Monday, when Alphabet Inc.’s Google Quantum AI unit published what some experts characterized as a potential breakthrough in the field that could accelerate the development of a commercially viable product.

Shares of all three of the small-cap companies named above briefly rallied on the news on Tuesday, although only one — Rigetti — managed to hang on to its gains by the time the closing bell rang. Shares of both IonQ and D-Wave Quantum continued to slide on Wednesday....

....MUCH MORE

We happened to catch the Google story via the NYT on Monday evening: "Quantum Computing Inches Closer to Reality After Another Google Breakthrough" (GOOG).

The next trading day it was up ~5%. Today it set a new all-time-high.

If interested we have quite a few posts on D-Wave and to a lesser extent Rigetti. Use the 'search blog' box upper left. 

One final word on risk. If an overvalued company you are short actually has some worthwhile technology there is a real risk that they might be acquired for that technology, which can wreck your whole day.

Or more importantly your annual bonus.

Computing: "D-Wave Launches Free Quantum Cloud Service"

From IEEE Spectrum, October 4:

Canadian company joins IBM and Rigetti in offering online access to pricey hardware

Quantum computing could someday supercharge artificial intelligence, accelerate drug discovery, and even reduce traffic jams. But existing quantum computers, which have only a modest, if any, advantage over their classical brethren, are expensive, finicky beasts. Even if you could afford the US $15 million to buy a D-Wave 2000Q quantum annealer [PDF], for example, you would need experts to maintain the ultracold operating conditions its processor requires.

Until today, that is, when Canadian startup D-Wave Systems Inc. launched a real-time online quantum computing environment called Leap. Leap is the latest addition to the quantum cloud—services that virtualize quantum computing for almost anyone with a computer and a broadband connection to use.

Leap allows anyone to sign up, giving them one minute of time on a cloud-connected 2000Q each month. That might not sound like much, but a key advantage of quantum computing is to be able to solve in milliseconds problems like factoring large numbers, optimizing routes, or calculating molecular structures that could take traditional computers days or weeks. Quantum computers encode information in qubits, enabling massively parallel computation relying on purely quantum effects.

“We want to enable hundreds of thousands or millions of developers to gain access to quantum computing technology, to understand it, and to develop applications,” says Murray Thom, D-Wave’s director of software and cloud services.

As well as granting access to a 2000Q computer housed at D-Wave’s headquarters in the Vancouver suburbs, Leap provides documentation, videos, training materials, and a community for the majority of developers who have never worked with a quantum computing device.

“There are a few people in materials simulation, finance, and machine learning who will understand quantum programming constructs in two or three sentences,” says Thom. “But the focus of our system is on folks who are new to quantum.”...

...MORE

Recently:
"10 Quantum Computing Startups Getting Funded in 2018"

Keeping in mind that Google is pretty fired up on D-Wave's architecture while Rigetti and Alibaba are developing proprietary systems....

Cloud-Based Quantum Computing Is Almost Ready For Business

Thus sayeth Rigetti:...

Quantum Stocks Drop as Nvidia CEO Sees Use Years Away

Could not agree more.*

From Bloomberg, January 8:

The shares of IonQ Inc. and other companies linked to quantum computing tumbled in premarket trading on Wednesday, after Nvidia Corp. Chief Executive Officer Jensen Huang said that “very useful” quantum computers are likely decades away.

“If you kind of said 15 years for very useful quantum computers, that would probably be on the early side. If you said 30, it’s probably on the late side,” Huang said in a question-and-answer session during Nvidia’s analyst day. “If you picked 20, I think a whole bunch of us would believe it.”

Shares in Quantum Computing Inc., D-Wave Quantum Inc. and Rigetti Computing Inc. dropped more than 14% in premarket trading, while IonQ fell about 10%. These stocks have soared in recent months amid excitement

about the technology’s potential, which was heightened last month following a quantum computing breakthrough by Alphabet Inc.

Read More: Alphabet Ends 2024 on High With Help From Quantum Tech Leap

Quantum Computing shares had gained more than 1,800% over the past 12 months to $17.49 through Tuesday’s close. Rigetti rose more than 1,500% to $18.39 over the same span, while D-Wave advanced nearly 1,000% to $9.55 and IonQ more than 300% to $49.59....

....MORE

As just one example of this morning's stock price moves, RGTI is down $3.72 (-20.23%) at $14.67 after falling 5.74% on Tuesday.

We had the Google story on December 9: "Quantum Computing Inches Closer to Reality After Another Google Breakthrough" (GOOG).

Followed by an editorial comment in the headline December 11: This is Goofy: "Quantum-computing stocks are soaring as investors place bets on ‘the next big thing’ in tech"

"Goofy," a term that exudes erudition on the part of the analyst. The rest of that post's comments on shorting are more pedestrian.

On December 26 the intro/outro from "2025 will be a 'show-me' year for nuclear: Expert":

We have been here before with the small modular reactors.*

***

*May 2024 - "Small modular nuclear reactors get a reality check in new report"

The fact they've been available for over a decade and not enthusiastically deployed hither and yon tells us there's something not quite commercially viable about the little nukes.

2012 - Surviving in Your Doomsday Bunker with Portable Nuclear Power to Spare

Ditto and double ditto for the quantum computing stocks. There will be at least one and possibly three bear markets before they are even close to earning money.

However, for the diehard next-big-thing wannabes we did link to Barron's "...How to Pretend You Understand Quantum Computing." on Dec 14.

"Ghost post! Google creates world’s most powerful computer, NASA ‘accidentally reveals’ ...and then publication vanishes"

A little conspiracy theorizing from RT on what was otherwise pretty straightforward news.
Quantum 'puters and AI are two areas that President Putin has directed Russia to focus on so whatever the boss wants RT delivers.

We've been following the D-Wave, Google, NSA quantum computer adventure for a while, more after the jump.
From the folks formerly known as Russia Today:

Google’s new quantum computer reportedly spends mere minutes on the tasks the world’s top supercomputers would need several millennia to perform. The media found out about this after NASA “accidentally” shared the firm’s research. 

 

The software engineers at Google have built the world’s most powerful computer, the Financial Times and Fortune magazine reported on Friday, citing the company’s now-removed research paper. The paper is said to have been posted on a website hosted by NASA, which partners with Google, but later quietly taken down, without explanation.

Google and NASA have refused to comment on the matter. A source within the IT giant, however, told Fortune that NASA had “accidentally” published the paper before its team could verify its findings.

In the research, Google reportedly claimed that it takes their new quantum processor just around 200 seconds to make calculations that existing supercomputers would require around 10,000 years to perform. They also said the processor requires mere 30 seconds to complete a task the Google Cloud server would need 50 trillion hours to do....MORE

I'm thinking the announcement was Google's to make not NASA's., so they pulled it.
Previously:
March 2019
"Inside the high-stakes race to make quantum computers work"
March 2019 
Quantum Computing That Is Actually Useful Gets A Bit Closer to Reality
October 2018
Computing: "D-Wave Launches Free Quantum Cloud Service"
October 2018
"10 Quantum Computing Startups Getting Funded in 2018"
Keeping in mind that Google is pretty fired up on D-Wave's architecture while Rigetti and Alibaba are developing proprietary systems.... 
September 2018
Cloud-Based Quantum Computing Is Almost Ready For Business
Thus sayeth Rigetti:...
March 2018 
TASS: A multi-qubit quantum computer could be created in Russia within a year
March 2018
Quantum Computing: "Volkswagen Refining Machine Learning on D-Wave System"
"Google and VW partner on quantum computing to improve electric car batteries"
Volkswagen Using D-Wave Quantum Computer To Fight Beijing Traffic (plus the VW Level 5 autonomous vehicle)
February 2018 
"The Argument Against Quantum Computers"
February 2018 
Supremecy—Quantum Algorithms Struggle Against Old Foe: Clever Computers
January 2018 
Breaking Bitcoin With a Quantum Computer
And the 2017 series:
Questions America Wants Answered: "Is Quantum Computing an Existential Threat to Blockchain Technology?"
Yeah, I Got Your Bitcoin Right Here: "‘Quantum Checks’ to Replace Cryptocurrencies in the Future?"
Computing: Will Quantum Devices Outperform Classical Computers by Year-end 2017? (thus achieving 'quantum supremecy')
The route to high-speed quantum computing is paved with error
"Google's Quantum AI Laboratory set out investment opportunities on the road to the ultimate quantum machines" (GOOG).

And many, many more. 

Including 2015's
"Google says it has now proven that D-Wave’s quantum computer really works" (GOOG) 
We have quite a few posts on D-Wave, links below, and through most of them our attitude was a dubious "Show me".
It appears they may have.

"Quantum gold rush: the private funding pouring into quantum start-ups"

Following up on Sept. 23's "Ghost post! Google creates world’s most powerful computer, NASA ‘accidentally reveals’ ...and then publication vanishes" 
—and a hundred other posts, some links after the jump.

From the journal Nature, October 2:

A Nature analysis explores the investors betting on quantum technology. 

Robert Schoelkopf spent more than 15 years studying the building blocks of quantum computers until, in 2015, he decided it was time to start constructing one. The physicist and his colleagues at Yale University began pitching their start-up firm Quantum Circuits, Inc. to investors, hoping to persuade venture capitalists that the time was ripe to pour cash into a quantum-computing company. Within two years, the team had secured US$18 million. That was enough to build a specialist laboratory — which opened this January — in a science park near the university in New Haven, Connecticut, and to employ around 20 scientists and engineers.

For Schoelkopf, venture capital (VC) investing was unfamiliar territory. But he’s not the only quantum physicist to make a successful sales pitch. Governments and large technology firms have long nurtured quantum research, and in the past few years have announced billions of dollars for the field. As their support has ramped up, outside investors have looked to get in early on a fledgling industry.

By the start of this year, according to an analysis by Nature, private investors had funded at least 52 quantum-technology companies globally since 2012 — many of them spin-outs from university departments. (Academics have founded many more start-ups that have yet to close deals.) Although the value of some of the cash infusions remains secret, Nature’s analysis captures the scale of recent activity. It finds that, in 2017 and 2018, companies received at least $450 million in private funding — more than four times the $104 million disclosed over the previous two years (see ‘Cash for qubits’). VC makes up the bulk of this cash. Many firms in the VC hub of California’s Silicon Valley have already plunged in, and among the rest, “most are keeping a close eye on quantum”, says Christopher Monroe, a physicist at the University of Maryland in College Park who co-founded the quantum-computing firm IonQ in 2015. 

Source: Nature analysis, including data from Quantum Computing Report, Boston Consulting Group, PitchBook and Crunchbase

Few doubt that quantum technologies will eventually yield useful and potentially revolutionary products. Alongside government investments, hundreds of firms are rushing to invest in the field, with big names such as IBM, Google, Alibaba, Hewlett Packard, Tencent, Baidu and Huawei all doing their own research. Google has reportedly now created a quantum computer that can solve specialized problems that would stump even the best classical computer — a landmark known as ‘quantum supremacy’. Secure encryption using quantum technology is already a commercial product, as are some quantum-enabled technologies that sense, image or measure at exquisitely precise scales. One firm, D-Wave Systems in Burnaby, Canada, even sells computers that exploit quantum effects, although these machines specialize in particular tasks known as optimization problems.

But venture capitalists tend to invest in what they hope will be game-changers, such as a multipurpose quantum computer that could handle many kinds of otherwise-unfeasible calculations. From the perspective of investors, the cash pumped into the field annually represents a small outlay so far — on a par with VC investments in artificial-intelligence (AI) firms before 2010, for instance. (By 2018, US VC investments in AI had boomed to $9.3 billion.) Still, these numbers are substantial for an immature field that doesn’t yet have much to sell. Despite this, some software firms are already marketing their work on quantum algorithms, which are written for hardware that does not yet exist....

....MUCH MORE

Also at Nature, Oct. 2:
Beyond quantum supremacy: the hunt for useful quantum computers

Way back in 2017 Nature was posting (and we were linking): "Google's Quantum AI Laboratory set out investment opportunities on the road to the ultimate quantum machines" (GOOG).

And some other links:
March 2019
"Inside the high-stakes race to make quantum computers work"
March 2019
Quantum Computing That Is Actually Useful Gets A Bit Closer to Reality
October 2018
Computing: "D-Wave Launches Free Quantum Cloud Service"
October 2018
"10 Quantum Computing Startups Getting Funded in 2018"
Keeping in mind that Google is pretty fired up on D-Wave's architecture while Rigetti and Alibaba are developing proprietary systems....
September 2018
Cloud-Based Quantum Computing Is Almost Ready For Business
Thus sayeth Rigetti:...
March 2018
TASS: A multi-qubit quantum computer could be created in Russia within a year
March 2018
Quantum Computing: "Volkswagen Refining Machine Learning on D-Wave System"

"Google and VW partner on quantum computing to improve electric car batteries"

Volkswagen Using D-Wave Quantum Computer To Fight Beijing Traffic (plus the VW Level 5 autonomous vehicle)
February 2018
"The Argument Against Quantum Computers"
February 2018
Supremecy—Quantum Algorithms Struggle Against Old Foe: Clever Computers
January 2018
Breaking Bitcoin With a Quantum Computer

And the 2017 series:
Questions America Wants Answered: "Is Quantum Computing an Existential Threat to Blockchain Technology?"
Yeah, I Got Your Bitcoin Right Here: "‘Quantum Checks’ to Replace Cryptocurrencies in the Future?"
Computing: Will Quantum Devices Outperform Classical Computers by Year-end 2017? (thus achieving 'quantum supremecy')
The route to high-speed quantum computing is paved with error
"Google's Quantum AI Laboratory set out investment opportunities on the road to the ultimate quantum machines" (GOOG).

And many, many more.

Including 2015's
"Google says it has now proven that D-Wave’s quantum computer really works" (GOOG)
We have quite a few posts on D-Wave, links below, and through most of them our attitude was a dubious "Show me".
It appears they may have. 

"D-Wave Lands $50M Funding for Next Generation Quantum Computers"

From Inside HPC:

Today D-Wave Systems announced that it has received up to $50 Million in funding from PSP Investments. This facility brings D-Wave’s total funding to approximately US$200 million. The new capital is expected to enable D-Wave to deploy its next-generation quantum computing system with more densely-connected qubits, as well as platforms and products for machine learning applications.

This commitment from PSP Investments is a strong validation of D-Wave’s leadership in quantum computing,” said Vern Brownell, CEO of D-Wave. “While other organizations are researching quantum computing and building small prototypes in the lab, the support of our customers and investors enables us to deliver quantum computing technology for real-world applications today. In fact, we’ve already demonstrated practical uses of quantum computing with innovative companies like Volkswagen. This new investment provides a solid base as we build the next generation of our technology.”

This latest funding comes on the heels of significant momentum for D-Wave. Milestones achieved so far in 2017 include:

The D-Wave 2000Q quantum computer launched with first customer. D-Wave launched a new computing system with 2000 qubits, enabling faster performance, and providing a major step toward production applications in optimization, cybersecurity, machine learning, and sampling. Cybersecurity company Temporal Defense Systems purchased the first D-Wave 2000Q system.

Cooperation with Virginia Tech. D-Wave established a joint effort with Virginia Tech’s Hume Center for National Security and Technology to provide greater access to quantum computers for researchers from the U.S. Intelligence Community and Department of Defense.

Google, NASA, and USRA elected to upgrade. their D-Wave 2X quantum computer to the new D-Wave 2000Q system, to support their pioneering research on how quantum computing can be applied to artificial intelligence, machine learning, and difficult optimization problems....

...MORE

Recently:
The route to high-speed quantum computing is paved with error
Quantum Computing Startup Rigetti Computing Raises $64 Million in Funding
The other day I mentioned that D-Wave wasn't yet a "real" quantum computer but that they were closer than anyone currently in production. Here's one of the up-and-comers.... 
Volkswagen Using D-Wave Quantum Computer To Fight Beijing Traffic (plus the VW Level 5 autonomous vehicle)

We have many, many more posts on both D-Wave in particular and quantum computing including this from Quanta magazine:
What Can Quantum Computers Be Used For?

Use the 'search blog' box if interested in more. 

Quantum Computing: "Volkswagen Refining Machine Learning on D-Wave System"

These guys ain't talkin' Fahrvergnügen, more after the jump.

From The Next Platform:

Researchers at Volkswagen have been at the cutting edge of implementing D-Wave quantum computers for a number of complex optimization problems, including traffic flow optimization, among other potential use cases.

These efforts are generally focused on developing algorithms suitable for the company’s recently purchased 2000-qubit quantum system and have expanded to a range of new machine learning possibilities, including what a research team at the company’s U.S. R&D office and the Volkswagen Data:Lab in Munich are calling quantum-assisted cluster analysis.

The art and science of clustering is well known for machine learning on classical computing architectures, but the VW approach that has been tailored to perform well on a quantum processor has undergone major alterations. As the team describes, to be mapped to the D-Wave architectures, the problem has to be expressed as a quadratic unconstrained  binary optimization problem. Once done, the accuracy of results is similar to the what a classical clustering algorithm can produce.

On the one hand, that begs the question about why it is necessary to add unnecessary complexity for similar results, but as we’ve covered here, any work on quantum algorithms now is adding to a critical baseline to build from, especially for annealing-based systems like D-Wave produces (as opposed to slightly more “recognizable” gate model quantum architectures from IBM, Rigetti, and others).

The traffic flow optimization problem VW researchers mapped to the D-Wav machine in 2017 was interesting, but one has to ask about the overall ROI of the investment ($15 million per D-Wave system) in both hardware and software research terms. What is the end result of optimized traffic flow for VW?...

...MORE

Previously:
"Google and VW partner on quantum computing to improve electric car batteries"
Volkswagen Using D-Wave Quantum Computer To Fight Beijing Traffic (plus the VW Level 5 autonomous vehicle)
"A graphical display of some very nervous VW execs and engineers…"

"As NVIDIA’s Quantum Day Nears, Analysts Suggest Event is More Than a Gesture" (NVDA)

You know what looks cheap? Nvidia looks cheap.

That's not to say it can't get cheaper but to quote some of the old-time traders: "Well bought is half sold."

$111.29 last, up $0.72 (+0.65%) in late pre-market trading.

Insider Brief

• NVIDIA’s Quantum Day at GTC 2025 is bringing together industry leaders to discuss the technology’s current capabilities and future potential.
• CEO Jensen Huang’s earlier skepticism about quantum computing’s timeline caused stock declines for several quantum companies, prompting NVIDIA to engage more directly with the quantum industry, analysts suggest.
• The event will feature discussions on quantum computing’s role in AI, commercialization challenges, and potential breakthroughs, with executives from leading quantum firms participating.
• Image: Google Quantum AI

NVIDIA’s inaugural Quantum Day at GTC 2025 — scheduled for March 20 — is closing in and anticipation is growing for the event, which will bring together industry leaders and researchers to discuss quantum computing’s present advances and future potential.

Initially, some in the quantum industry — and perhaps in the larger tech industry — viewed NVIDIA’s decision to host its first Quantum Day as more of an apology and slightly an apology. However, the event is now seen as more than a simple industry gathering and more than a gesture to the quantum computing community — it’s a statement, according to Investor’s Business Daily, who asked analysts and key figures to break down the events that led to the Quantum Day announcement.

After CEO Jensen Huang’s remarks — that quantum computing would not be “very useful” for 15 to 30 years — in January sent quantum computing stocks plummeting, the tech giant is now bringing industry leaders together to discuss the technology’s future. The move suggests NVIDIA is recalibrating its stance and recognizing quantum computing’s potential sooner rather than later, according to IBD.

“If NVIDIA really thought that quantum was 15 to 30 years out, would they have an event today? Probably not,” Gil Luria, an analyst at D.A. Davidson and head of the firm’s technology research, told IBD.

The GTC event in Silicon Valley — a highlight on the tech conference calendar — will feature quantum executives, including D-Wave CEO Alan Baratz, who was personally invited by Huang shortly after the controversy erupted.

The Fallout From Huang’s Comments

Huang’s comments at CES had an immediate impact. Investors panicked, causing shares of Rigetti Computing, IonQ, D-Wave, and Quantum Computing Inc. to drop sharply.

Luria, who had just given a quantum company a buy rating, knew the quote would have impact.

“When I heard that, I rolled my eyes a little bit,” Luria told IBD. “But I realized that that was going to have an impact.”

Baratz was among the most vocal in pushing back.

“The quantum computing industry is still young, and the investor market is still maturing,” Baratz said, according to IBD. “Everybody’s looking for any information that they can use to make decisions. Sometimes misinformation can get out there and drive decisions.”

Quantum computing companies argue that real-world applications already exist, with businesses exploring the technology for supply chain optimization, drug discovery and financial modeling. Others, including veteran Silicon Valley investors, argue that large-scale commercial viability is still years away.....

....MUCH MORE

Although we see no rush to own the current batch of publicly traded names, we do pay attention to what the chatter is. Some of our previous links and more recent comments were wrapped in January 8's "Quantum Stocks Drop as Nvidia CEO Sees Use Years Away":

Ditto and double ditto for the quantum computing stocks. There will be at least one and possibly three bear markets before they are even close to earning money.

However, for the diehard next-big-thing wannabes we did link to Barron's "...How to Pretend You Understand Quantum Computing." on Dec 14.

Here's Nvidia:

NVIDIA GTC 2025: Quantum Day to Illuminate the Future of Quantum Computing

NVIDIA CEO Jensen Huang and Industry Visionaries to Unveil What’s Next in AI at GTC 2025

Quantum Day Conference Sessions

The Market for Quantum Technology: Early Revenue-Generating Applications

From EE Times, October 26:

Quantum technology comprises quantum computing, quantum cryptography, quantum networking (the Quantum Internet) and quantum sensors.  All of these sectors of quantum technology are already generating revenues today.  Apart from quantum sensors, all are interrelated in important ways, with the prospect of commercial quantum computing driving much of the investment in the emerging quantum technology market.  Quantum sensors use the sensitivity of quantum devices to increase the effectiveness of medical imagining, global positioning and other applications.  They are real and with us today, but I won’t have much to say about them in this article

Quantum Computing:  State of Play
As recently as two years ago articles were appearing from serious critics saying that quantum computers weren’t buildable in practice.  Today, much of that skepticism has dissipated; tier-one firms are investing in quantum computing.

Quantum computers or their components/access networks have already been developed by Alibaba, Amazon, IBM, Microsoft, Google, Honeywell, and Intel.  Also playing in this market are well-funded newer companies such as Rigetti, ionQ and D-Wave.

The involvement of household names like IBM, Google or Amazon not only adds credibility to quantum computing but also spreads its fame.  With such firms involved in this market, it is easy to get quantum computers onto the home pages of news outlets that ordinarily don’t cover advanced physics or supercomputing.

How quantum computers work and the applications they can solve:

This seems like a good place to attempt an explanation of how a quantum computer works.  A full explanation is well beyond the scope of this article, but suffice it to say that quantum computers perform calculations based on the probability of an object’s quantum state before it is measured.  This is compared to what a classical computer does — calculated on the basis of deterministic 1s or 0s.

At the practical level, this translates into quantum computers being able to process orders of magnitude more information than classical computers can in the same period of time.  So quantum computers embody a promise that quantum computers can solve problems that classical problems cannot solve in a reasonable time period.

Although quantum computers are already in use, there is some agreement that there are, as yet, no practical problems that can be solved by a quantum computer that cannot be solved by a classical computer.  This is a very controversial issue – but this so-called quantum advantage has supposedly been demonstrated for classes of theoretical problems. The areas where quantum computers have been found to be especially useful to date have been in optimization programs, artificial intelligence, and machine learning, and in simulation.

None of this is intended to imply that progress in quantum computing technology will be easy.  While the capacity of quantum computers is measured in qubits (not bits like classical computers), the quality of the qubits is also important.  It is difficult to maintain the quantum states of qubits as they are prone to quantum decoherence.  Quantum computers require significant error correction since they are more prone to errors than classical computers.

Some of the firms mentioned above are making quantum hardware and selling them to end-users.  Some are selling access to their computers over a dedicated cloud, making the otherwise enormously expensive quantum computers ($10 million -$15 million) accessible to thousands of users.  There is also a slew of companies (including Intel) that are developing processors for future quantum computers.

Banks, Investment and Quanta
Probably the biggest markets for quantum computers in the past few years have been R&D and government (including the military and the intelligence community).  This is typical of new computing products.  But in the view of Inside Quantum Technology, the market where we think quantum computing will first find big commercial success (the “killer app” for quantum computing?) is in the financial services sector (banks, insurance companies, investment firms, etc.)....

....MUCH MORE

The route to high-speed quantum computing is paved with error

Here's a re-re-reference, yesterday's "Quantum Computing Startup Rigetti Computing Raises $64 Million in Funding":

The other day I mentioned that D-Wave wasn't yet a "real" quantum computer but that they were closer than anyone currently in production. Here's one of the up-and-comers....

And more on the current state of the art from Ars Technica:

Quantum computing: Fast, rough, and repeat, or slow, precise, and right?

When it comes to quantum computing, mostly I get excited about experimental results rather than ideas for new hardware. New devices—or new ways to implement old devices—may end up being useful, but we won't know for sure when the results are in. If we are to grade existing ideas by their usefulness, then adiabatic quantum computing has to be right up there, since you can use it to perform some computations now. And at this point, adiabatic quantum computing has the best chance of getting the number of qubits up.

But qubits aren't everything—you also need speed. So how, exactly, do you compare speeds between quantum computers? If you begin looking into this issue, you'll quickly learn it's far more complicated than anyone really wanted it to be. Even when you can compare speeds today, you also want to be able to estimate how much better you could do with an improved version of the same hardware. This, it seems, often proves even more difficult.

It's fast, honest
Unlike classical computing, speed itself is not so easy to define for a quantum computer. If we just take something like D-Wave's quantum annealer as an example, it has no system clock, and it doesn't use gates that perform specific operations. Instead, the whole computer goes through a continuous evolution from the state in which it was initialized to the state that, hopefully, contains the solution. The time that takes is called the annealing time.

At this point, you can all say, "Chris ur dumb, clearly the time from initialization to solution is what counts." Except, I used the word hopefully in that sentence above for good reason. No matter how a quantum computer is designed and operated, the readout process involves measuring the states of the qubits. That means there is a non-zero probability of getting the wrong answer.

This does not mean that a quantum computer is useless. First, for some calculations, it is possible to check a solution very efficiently. Finding prime factors is a good example. I simply multiply the factors together; if the answer doesn't come to the number I initialized the computer with, I know it got it wrong. In case of a wrong answer, I simply repeat the computation. When you can't efficiently check the solution, you can rely on statistics: the correct answer is the most probable outcome of any measurement of the final state. I can just run the same computation multiple times and determine the correct answer from the statistical distribution of the results.

So for an adiabatic quantum computer, this means speed is the annealing time multiplied by the number of runs required to determine the most probable outcome. While not the most satisfactory answer, it's still better than nothing.

Unfortunately, these two factors are not independent of each other. During annealing, the computation requires that all the qubits stay in the ground state. However, fast changes are more likely to disturb the qubits out of the ground state—so decreasing the annealing time increases the probability of getting an incorrect result. Do the work faster, and you may need to perform the computation more times to correctly determine the most probable outcome. And as you decrease the annealing time, wrong answers will eventually become so probable that they are indistinguishable from correct answers.

So determining the annealing time of an adiabatic quantum computer has something of a trial-and-error approach to it. The underlying logic is that slower is probably better, but we'll go as fast as we dare. A new paper published in Physical Review Letters shows that, actually, under the right conditions, it might be better to throw caution to the wind and speed up even more. However, that speed comes at the cost of high peak power consumption....MORE