QuEra’s Quest: Build a Flexible Neutral Atom-based Quantum Computer

By John Russell

November 23, 2022

Last month, QuEra Computing began providing access to its 256-qubit, neutral atom-based quantum system, Aquila, from Amazon Braket. Founded in 2018, and built on technology developed at Harvard and MIT, QuEra, is one of a growing number of quantum companies betting on neutral atom technology. Advocates, including QuEra, say neutral atom approaches feature significant advantages over other approaches such as semiconductor-based superconducting systems, which require frigid operating temperatures and pose significant control and scaling challenges.

Among the companies betting on neutral atom-based qubit technology are QuEra, Pasqal, Atom Computing, and ColdQuanta. Their progress has steadily brought more visibility and now user access to emerging neutral atom-based quantum systems. QuEra’s recent launch on Amazon Braket is a good example and is another step forward for neutral atom qubit technology.

A distinguishing part of QuEra’s roadmap is to offer analog quantum computing first, hybrid analog-gate-based solutions next, and finally full, fault-tolerant gate-based systems. Pasqal is following a somewhat similar approach. Currently both are focused on delivering analog quantum systems. It’s probably worth noting that 20-year-old D-Wave Systems, which pioneered semiconductor-based quantum annealing computing, has recently expanded its roadmap to include development of gate-based systems.

Most of the work in quantum computing today focuses on gate-based systems. That by-now familiar idea is that gate-based systems are universal and will be able to tackle all computational tasks. The other main approach is analog quantum computing – similar to what D-Wave does, although it does not prefer that term. Quantum analog systems work differently. Instead of performing a series of individual gate functions, which constitute a quantum program, the problem to be solved is formulated in a way that it can be directly mapped onto a collection of qubits. The system is allowed to evolve as a whole, much as it would in nature. (Various techniques allow for some guiding of the evolution.)

In a real sense, analog quantum simulation is more of an experiment resembling the original question – it’s a kind of quantum wind tunnel, if you will, in which the mapped system behaves as it would in nature with all the quantum physics baked in. Like all quantum computers, the results are probabilistic, so you run the problem many times to get a distribution of results which presumably will spotlight the desired (usually, the dominant) result. It turns out there are variety of problems, including select simulations and optimizations, that can be solved this way, and recent work by QuEra and Pasqal have demonstrated such systems can be effective for maximum independent set problems (QuEra paper) and quantum evolution kernel methods (Pasqal paper).

Alex Keesling, QuEra CEO

“We are strong believers, right now, that the most advantage that you can get from existing quantum hardware comes from applications that are designed to run efficiently on the hardware, not these abstract, hardware-agnostic approaches,” said Alex Keesling, QuEra CEO in a briefing with HPCwire.

QuEra’s neutral atom approach to quantum computing is fascinating. Basically, a cloud of appropriate neutral atoms – QuEra uses rubidium – are placed in an evacuated chamber. Focused lasers are shined into the chamber and used to create a pattern of sticky spots in which individual atoms become trapped in a 2-dimensional array. The atoms, by their nature, are identical, avoiding many manufacturing worries. More importantly, the trapped atoms can then be exquisitely manipulated and moved around by lasers.

“We don’t need to worry about cryogenic systems. All we have is a small vacuum chamber. Using light through lasers and magnetic fields we can slow down atoms to basically a standstill, and then focus lasers down very tightly to hold the atoms in place,” said Keesling. Lasers are also used to control the state of individual rubidium atoms, whose valence electron can be put into a hyperfine state (spin, representing one or zero). Because the atoms are neutral – unlike ions which repel each other – they can be packed tightly together.

“We can currently pack up to 256 atoms and expect very soon to have 1,000 atoms. This system, without having to reinvent anything, can easily go to 10,000 or more,” said Keesling.

Entanglement between atoms, which are the system’s qubits, is accomplished by pumping up the atoms into a Rydberg state – basically the atom’s outer shell expands. By bringing Rydberg atoms close enough together so their shells overlap, you can cause them to become entangled.

“So, we can isolate individual atoms and we can control their internal state [and] define zero and one for the atom. One of the great things about the platform is that it allows us to take images of the atoms in real time, and then move them around to position them in whatever configuration we want them to be,” said Keesling. An important QuEra advance has been development of the ability to move individual atoms or groups of atoms with great precision (and reasonable speed). That way, encoded qubits can be placed where needed for a particular problem map.

“This is important, because the connectivity is given by the relative position of our atomic qubits.  We can define the connectivity of our ‘quantum chip equivalent’, if you will, at every fraction of a second when we run the machine; this gives us the advantage of being able to encode problems efficiently into the configuration of the atoms basically ‘on the chip’ and we don’t have to go back to a manufacturing facility to build a new chip. We can do this on the fly,” he said.

Broadly speaking, the Rydberg-entanglement range has limits. Keesling said QuEra can get beyond nearest neighbor entanglement to “next nearest neighbor or even third nearest neighbor, and using a few other tricks, you can extend this range more and more, but we actually see a lot of value in having this interplay between things that interact locally.” This ability to relocate encoded qubits, says Keeling, will be the basis of eventual gate-based system.

Right now, said Keesling, “It’s this local connectivity in the analog mode of operation [that] is very helpful for us to effectively draw networks or graphs on the connectivity [in the system], and directly encode some hard, combinatorial optimization problems, and then solve them through this analog evolution of the system.”

Most of the underlying work for QuEra came from the labs of co-founders Mikhail Lukin (Harvard), Vladan Vuletic (MIT), Markus Griener (Harvard) and Dirk Englund (MIT). QuEra has an impressive list of science papers on its website. A fair amount of work is proceeding on identifying application areas and techniques. The company currently has a paper still under peer review but accessible on ArXiv – Quantum optimization with arbitrary connectivity using Rydberg atom arrays – that presents ideas for extending optimization techniques used on its neutral atom platforms. Here’s the abstract:

“Programmable quantum systems based on Rydberg atom arrays have recently been used for hardware-efficient tests of quantum optimization algorithms with hundreds of qubits. In particular, the maximum independent set problem on the so-called unit-disk graphs, was shown to be efficiently encodable in such a quantum system. Here, we extend the classes of problems that can be efficiently encoded in Rydberg arrays by constructing explicit mappings from the original computation problems to maximum weighted independent set problems on unit-disk graphs, with at most a quadratic overhead in the number of qubits.

“We analyze several examples, including: maximum weighted independent set on graphs with arbitrary connectivity, quadratic unconstrained binary optimization problems with arbitrary or restricted connectivity, and integer factorization. Numerical simulations on small system sizes indicate that the adiabatic time scale for solving the mapped problems is strongly correlated with that of the original problems. Our work provides a blueprint for using Rydberg atom arrays to solve a wide range of combinatorial optimization problems with arbitrary connectivity, beyond the restrictions imposed by the hardware geometry.”

Keesling would say little about applications currently being explored by early users. “We have a few ongoing collaborations. I can’t really disclose them. But I can tell you that we basically see two buckets of applications. One is simulation [or] building quantum twins, as you put it – I really like the wording – and the second is optimization problems.”

The company has developed software, Bloqade – “Bloqade enables benchmarking and algorithmic design, incorporating the core strengths of neutral-atom arrays for quantum computing. Accounting for features such as Julia, flexible processor geometry, multi-qubit connectivity, and analog operation modes, Bloqade is an open-sourced community tool.” Bloqade can be downloaded from GitHub or run on Amazon Braket.

By making Aquila available from AWS Braket, QuEra is taking an important step in building its user base and market presence.

In the announcement, Simone Severini, director of quantum computing at AWS, said, “AWS is deeply focused on bringing our customers choice on Amazon Braket to explore scientific research and software development for quantum computing. The addition of Aquila brings neutral atom quantum computing capabilities to everyone on Amazon Braket for the first time. QuEra’s offering helps expand the types of applications that can be performed through Amazon Braket and is a valuable addition for customers focused on exploring neutral atom computing.”

One of the testimonials in the AWS announcement came from Ignacio Cirac, director and head of theory division, Max Planck Institute for Quantum Optics (MPQ), who said, “Special purpose analog quantum devices are likely to outperform classical computation for direct simulation of other quantum systems before we realize a fault-tolerant, universal quantum computer.”

At the moment, QuEra’s Aquila is indeed a special purpose device. It will be interesting to monitor how much interest and use its attracts. One advantage in the near-term goal of pursuing analog quantum computing first is the relative ease with which system size can be increased; while there are hurdles, implementing active error correction isn’t one of them as it isn’t required for analog quantum computing. Error correction is essential for scaling up gate-based quantum systems.

Long-term though, QuEra has much bigger goals.

“Right now we have the purely analog [platform] but then the next jump is going to be to bring online some of the capabilities that allow us to turn this into a hybrid analog-digital [system],” said Keesling. “Partly, the way to do this is to go beyond the idea of the qubit and go to a qudit, meaning something that has three states. That is something that we have in the works. That’s the first step towards enabling more of these capabilities, where we can do more analog evolution where it makes sense and then digital changes to the product to do a more complex kind of computation with it.”

Keesling said, “Going to a fully digital system – that is going to take some time because what we’re building is an architecture that is meant to support logical qubits as the operating unit. We’re looking at a few years still to make that transition full. But we expect that even in the hybrid analog-digital version of our systems, people will be able go digital and have no analog part to it.”

Stay tuned.

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

2022 Road Trip: NASA Ames Takes Off

November 25, 2022

I left Dallas very early Friday morning after the conclusion of SC22. I had a race with the devil to get from Dallas to Mountain View, Calif., by Sunday. According to Google Maps, this 1,957 mile jaunt would be the longe Read more…

2022 Road Trip: Sandia Brain Trust Sounds Off

November 24, 2022

As the 2022 Great American Supercomputing Road Trip carries on, it’s Sandia’s turn. It was a bright sunny day when I rolled into Albuquerque after a high-speed run from Los Alamos National Laboratory. My interview su Read more…

2022 HPC Road Trip: Los Alamos

November 23, 2022

With SC22 in the rearview mirror, it’s time to get back to the 2022 Great American Supercomputing Road Trip. To refresh everyone’s memory, I jumped in the car on November 3rd and headed towards SC22 in Dallas, stoppi Read more…

Chipmakers Looking at New Architecture to Drive Computing Ahead

November 23, 2022

The ability to scale current computing designs is reaching a breaking point, and chipmakers such as Intel, Qualcomm and AMD are putting their brains together on an alternate architecture to push computing forward. The chipmakers are coalescing around the new concept of sparse computing, which involves bringing computing to data... Read more…

QuEra’s Quest: Build a Flexible Neutral Atom-based Quantum Computer

November 23, 2022

Last month, QuEra Computing began providing access to its 256-qubit, neutral atom-based quantum system, Aquila, from Amazon Braket. Founded in 2018, and built on technology developed at Harvard and MIT, QuEra, is one of Read more…

AWS Solution Channel

Shutterstock 1648511269

Avoid overspending with AWS Batch using a serverless cost guardian monitoring architecture

Pay-as-you-go resources are a compelling but daunting concept for budget conscious research customers. Uncertainty of cloud costs is a barrier-to-entry for most, and having near real-time cost visibility is critical. Read more…

 

shutterstock_1431394361

AI and the need for purpose-built cloud infrastructure

Modern AI solutions augment human understanding, preferences, intent, and even spoken language. AI improves our knowledge and understanding by delivering faster, more informed insights that fuel transformation beyond anything previously imagined. Read more…

SC22’s ‘HPC Accelerates’ Plenary Stresses Need for Collaboration

November 21, 2022

Every year, SC has a theme. For SC22 – held last week in Dallas – it was “HPC Accelerates”: a theme that conference chair Candace Culhane said reflected “how supercomputing is continuously changing the world by Read more…

Chipmakers Looking at New Architecture to Drive Computing Ahead

November 23, 2022

The ability to scale current computing designs is reaching a breaking point, and chipmakers such as Intel, Qualcomm and AMD are putting their brains together on an alternate architecture to push computing forward. The chipmakers are coalescing around the new concept of sparse computing, which involves bringing computing to data... Read more…

QuEra’s Quest: Build a Flexible Neutral Atom-based Quantum Computer

November 23, 2022

Last month, QuEra Computing began providing access to its 256-qubit, neutral atom-based quantum system, Aquila, from Amazon Braket. Founded in 2018, and built o Read more…

SC22’s ‘HPC Accelerates’ Plenary Stresses Need for Collaboration

November 21, 2022

Every year, SC has a theme. For SC22 – held last week in Dallas – it was “HPC Accelerates”: a theme that conference chair Candace Culhane said reflected Read more…

Quantum – Are We There (or Close) Yet? No, Says the Panel

November 19, 2022

For all of its politeness, a fascinating panel on the last day of SC22 – Quantum Computing: A Future for HPC Acceleration? – mostly served to illustrate the Read more…

RISC-V Is Far from Being an Alternative to x86 and Arm in HPC

November 18, 2022

One of the original RISC-V designers this week boldly predicted that the open architecture will surpass rival chip architectures in performance. "The prediction is two or three years we'll be surpassing your architectures and available performance with... Read more…

Gordon Bell Special Prize Goes to LLM-Based Covid Variant Prediction

November 17, 2022

For three years running, ACM has awarded not only its long-standing Gordon Bell Prize (read more about this year’s winner here!) but also its Gordon Bell Spec Read more…

2022 Gordon Bell Prize Goes to Plasma Accelerator Research

November 17, 2022

At the awards ceremony at SC22 in Dallas today, ACM awarded the 2022 ACM Gordon Bell Prize to a team of researchers who used four major supercomputers – inclu Read more…

Gordon Bell Nominee Used LLMs, HPC, Cerebras CS-2 to Predict Covid Variants

November 17, 2022

Large language models (LLMs) have taken the tech world by storm over the past couple of years, dominating headlines with their ability to generate convincing hu Read more…

Nvidia Shuts Out RISC-V Software Support for GPUs 

September 23, 2022

Nvidia is not interested in bringing software support to its GPUs for the RISC-V architecture despite being an early adopter of the open-source technology in its GPU controllers. Nvidia has no plans to add RISC-V support for CUDA, which is the proprietary GPU software platform, a company representative... Read more…

RISC-V Is Far from Being an Alternative to x86 and Arm in HPC

November 18, 2022

One of the original RISC-V designers this week boldly predicted that the open architecture will surpass rival chip architectures in performance. "The prediction is two or three years we'll be surpassing your architectures and available performance with... Read more…

AWS Takes the Short and Long View of Quantum Computing

August 30, 2022

It is perhaps not surprising that the big cloud providers – a poor term really – have jumped into quantum computing. Amazon, Microsoft Azure, Google, and th Read more…

Chinese Startup Biren Details BR100 GPU

August 22, 2022

Amid the high-performance GPU turf tussle between AMD and Nvidia (and soon, Intel), a new, China-based player is emerging: Biren Technology, founded in 2019 and headquartered in Shanghai. At Hot Chips 34, Biren co-founder and president Lingjie Xu and Biren CTO Mike Hong took the (virtual) stage to detail the company’s inaugural product: the Biren BR100 general-purpose GPU (GPGPU). “It is my honor to present... Read more…

Tesla Bulks Up Its GPU-Powered AI Super – Is Dojo Next?

August 16, 2022

Tesla has revealed that its biggest in-house AI supercomputer – which we wrote about last year – now has a total of 7,360 A100 GPUs, a nearly 28 percent uplift from its previous total of 5,760 GPUs. That’s enough GPU oomph for a top seven spot on the Top500, although the tech company best known for its electric vehicles has not publicly benchmarked the system. If it had, it would... Read more…

AMD Thrives in Servers amid Intel Restructuring, Layoffs

November 12, 2022

Chipmakers regularly indulge in a game of brinkmanship, with an example being Intel and AMD trying to upstage one another with server chip launches this week. But each of those companies are in different positions, with AMD playing its traditional role of a scrappy underdog trying to unseat the behemoth Intel... Read more…

JPMorgan Chase Bets Big on Quantum Computing

October 12, 2022

Most talk about quantum computing today, at least in HPC circles, focuses on advancing technology and the hurdles that remain. There are plenty of the latter. F Read more…

UCIe Consortium Incorporates, Nvidia and Alibaba Round Out Board

August 2, 2022

The Universal Chiplet Interconnect Express (UCIe) consortium is moving ahead with its effort to standardize a universal interconnect at the package level. The c Read more…

Leading Solution Providers

Contributors

Using Exascale Supercomputers to Make Clean Fusion Energy Possible

September 2, 2022

Fusion, the nuclear reaction that powers the Sun and the stars, has incredible potential as a source of safe, carbon-free and essentially limitless energy. But Read more…

Nvidia, Qualcomm Shine in MLPerf Inference; Intel’s Sapphire Rapids Makes an Appearance.

September 8, 2022

The steady maturation of MLCommons/MLPerf as an AI benchmarking tool was apparent in today’s release of MLPerf v2.1 Inference results. Twenty-one organization Read more…

Not Just Cash for Chips – The New Chips and Science Act Boosts NSF, DOE, NIST

August 3, 2022

After two-plus years of contentious debate, several different names, and final passage by the House (243-187) and Senate (64-33) last week, the Chips and Science Act will soon become law. Besides the $54.2 billion provided to boost US-based chip manufacturing, the act reshapes US science policy in meaningful ways. NSF’s proposed budget... Read more…

SC22 Unveils ACM Gordon Bell Prize Finalists

August 12, 2022

Courtesy of the schedule for the SC22 conference, we now have our first glimpse at the finalists for this year’s coveted Gordon Bell Prize. The Gordon Bell Pr Read more…

Intel Is Opening up Its Chip Factories to Academia

October 6, 2022

Intel is opening up its fabs for academic institutions so researchers can get their hands on physical versions of its chips, with the end goal of boosting semic Read more…

AMD Previews 400 Gig Adaptive SmartNIC SOC at Hot Chips

August 24, 2022

Fresh from finalizing its acquisitions of FPGA provider Xilinx (Feb. 2022) and DPU provider Pensando (May 2022) ), AMD previewed what it calls a 400 Gig Adaptive smartNIC SOC yesterday at Hot Chips. It is another contender in the increasingly crowded and blurry smartNIC/DPU space where distinguishing between the two isn’t always easy. The motivation for these device types... Read more…

Google Program to Free Chips Boosts University Semiconductor Design

August 11, 2022

A Google-led program to design and manufacture chips for free is becoming popular among researchers and computer enthusiasts. The search giant's open silicon program is providing the tools for anyone to design chips, which then get manufactured. Google foots the entire bill, from a chip's conception to delivery of the final product in a user's hand. Google's... Read more…

AMD’s Genoa CPUs Offer Up to 96 5nm Cores Across 12 Chiplets

November 10, 2022

AMD’s fourth-generation Epyc processor line has arrived, starting with the “general-purpose” architecture, called “Genoa,” the successor to third-gen Eypc Milan, which debuted in March of last year. At a launch event held today in San Francisco, AMD announced the general availability of the latest Epyc CPUs with up to 96 TSMC 5nm Zen 4 cores... Read more…

  • arrow
  • Click Here for More Headlines
  • arrow
HPCwire