In developing the OPX1000, a controller fit for the ever-growing quantum processors counting 1,000 qubits and beyond, we had to think deeply about every detail that impairs scalability. Our recently unveiled OPX1000 module for microwave generation (MW-FEM) generates pulses up to 10.5 GHz directly, without analog oscillators or mixers. The choice of technology to reach microwave frequencies is not trivial. We choose cutting-edge direct digital synthesis (DDS) for very specific reasons, and we believe it will enable scalability and performance to an even greater degree. In this blog, we dive deeper into the considerations for going this route and existing alternatives. So stick around, whether you like mixers or hate them, this will be an interesting ride.

Summary of Technologies for Microwave Operation
The control signals for qubit drive and readout often fall in the microwave range, which is outside the range of baseband controllers. Many qubit labs have solved the issue with solutions based on mixing, including single sideband mixers, IQ-mixers, or more complicated schemes such as double super-heterodyne (DSH) conversion. Mixer-based solutions make use of analog local oscillators (LOs) that are multiplied by the signal of a controller or an AWG. IQ-mixers naturally suffer from two main spurs (affectionate name for unwanted signals), the LO leakage and the mixer image, which require non-trivial calibration to be removed. Other schemes, such as double super-heterodyne, offer a zero-calibration solution but use many more components. Additionally, mixing schemes require having an LO source per mixer if different drive frequencies are used. Having a low phase source per mixer is very expensive, and in order to cut prices, will probably include a phase-lock loops (PLL), leading to phase differences between channels, which is detrimental for multi-qubit systems. In other words, while mixers can be useful, we need to be aware of the pros and cons involved.

Quantum coherence at room temperature has been achieved, thanks to the efforts of Associate Professor Nobuhiro Yanai and his research team at Kyushu University's Faculty of Engineering. Additional credit goes to Associate Professor Kiyoshi Miyata (also of Kyushu University) and Professor Yasuhiro Kobori of Kobe University, all in Japan. Their scientific experiments have led to an ideal set of conditions where it is "crucial to generate quantum spin coherence in the quintet sublevels by microwave manipulation at room temperature." A quantum system requires operation in a stable state over a certain period of time, free of environmental interference.

Kobori-san has disclosed multi-department research results in a very elaborate document: "This is the first room-temperature quantum coherence of entangled quintets." The certain period of time mentioned above was only measures in nanoseconds, so more experimental work and further refinement will be carried out to prolong harmonious conditions. Head honco, Professor Yanai outlined some goals: "It will be possible to generate quintet multiexciton state qubits more efficiently in the future by searching for guest molecules that can induce more such suppressed motions and by developing suitable MOF structures...This can open doors to room-temperature molecular quantum computing based on multiple quantum gate control and quantum sensing of various target compounds."

Rigetti Computing, Inc. (Nasdaq: RGTI) ("Rigetti" or the "Company"), a pioneer in full-stack quantum-classical computing, announced today the launch of its Novera QPU, a 9-qubit quantum processing unit (QPU) based on the Company's fourth generation Ankaa -class architecture featuring tunable couplers and a square lattice for denser connectivity and fast 2-qubit operations. The Novera QPU is manufactured in Rigetti's Fab-1, the industry's first dedicated and integrated quantum device manufacturing facility.

The Novera QPU includes all of the hardware below the mixing chamber plate (MXC) of a dilution refrigerator. In addition to a 9-qubit chip with a 3x3 array of tunable transmons, the Novera QPU also includes a 5-qubit chip with no tunable couplers or qubit-qubit coupling which can be used for developing and characterizing single-qubit operations on a simpler circuit. In addition to the 9-qubit and 5-qubit chips, Novera QPU components include:

Alice & Bob, a leading hardware developer in the race to fault tolerant quantum computers, today announced the tape out of a new chip expected to improve error rates with every qubit added, making it a prototype for the company's first error-corrected, logical qubit.

The 16-qubit quantum processing unit (QPU), Helium 1, is the first chip in Alice & Bob's roadmap combining cat qubits to run an error correction code. The company will be able to use this platform to create its first logical qubit with error rates lower than any existing single physical qubit. With the tape-out complete, the chip enters a characterization and calibration phase that will be followed by a release on the cloud.

Atom Computing announced it has created a 1,225-site atomic array, currently populated with 1,180 qubits, in its next-generation quantum computing platform. This is the first time a company has crossed the 1,000-qubit threshold for a universal gate-based system, planned for release next year. It marks an industry milestone toward fault-tolerant quantum computers capable of solving large-scale problems.

CEO Rob Hays said rapid scaling is a key benefit of Atom Computing's unique atomic array technology. "This order-of-magnitude leap - from 100 to 1,000-plus qubits within a generation - shows our atomic array systems are quickly gaining ground on more mature qubit modalities," Hays said. "Scaling to large numbers of qubits is critical for fault-tolerant quantum computing, which is why it has been our focus from the beginning. We are working closely with partners to explore near-term applications that can take advantage of these larger scale systems."

Fault-tolerant quantum computers that offer radical new solutions to some of the world's most pressing problems in medicine, finance and the environment, as well as facilitating a truly widespread use of AI, are driving global interest in quantum technologies. Yet the various timetables that have been established for achieving this paradigm require major breakthroughs and innovations to remain achievable, and none is more pressing than the move from merely physical qubits to those that are fault-tolerant.

In one of the first meaningful steps along this path, scientists from Quantinuum, the world's largest integrated quantum computing company, along with collaborators, have demonstrated the first fault-tolerant method using three logically-encoded qubits on the Quantinuum H1 quantum computer, Powered by Honeywell, to perform a mathematical procedure.

Today, Intel announced the release of its newest quantum research chip, Tunnel Falls, a 12-qubit silicon chip, and it is making the chip available to the quantum research community. In addition, Intel is collaborating with the Laboratory for Physical Sciences (LPS) at the University of Maryland, College Park's Qubit Collaboratory (LQC), a national-level Quantum Information Sciences (QIS) Research Center, to advance quantum computing research.

"Tunnel Falls is Intel's most advanced silicon spin qubit chip to date and draws upon the company's decades of transistor design and manufacturing expertise. The release of the new chip is the next step in Intel's long-term strategy to build a full-stack commercial quantum computing system. While there are still fundamental questions and challenges that must be solved along the path to a fault-tolerant quantum computer, the academic community can now explore this technology and accelerate research development."—Jim Clarke, director of Quantum Hardware, Intel

Today at Commercialising Quantum Global 2023, IonQ (NYSE: IONQ), an industry leader in quantum computing, announced the availability of IonQ Aria on Amazon Braket, AWS's quantum computing service. This expands upon IonQ's existing presence on Amazon Braket, following the debut of IonQ's Harmony system on the platform in 2020. With broader access to IonQ Aria, IonQ's flagship system with 25 algorithmic qubits (#AQ)—more than 65,000 times more powerful than IonQ Harmony—users can now explore, design, and run more complex quantum algorithms to tackle some of the most challenging problems of today.

"We are excited for IonQ Aria to become available on Amazon Braket, as we expand the ways users can access our leading quantum computer on the most broadly adopted cloud service provider," said Peter Chapman, CEO and President, IonQ. "Amazon Braket has been instrumental in commercializing quantum, and we look forward to seeing what new approaches will come from the brightest, most curious, minds in the space."

IonQ, Inc. (NYSE: IONQ), an industry leader in quantum computing, today announced plans to open the first known dedicated quantum computing manufacturing facility in the U.S., located in the suburbs of Seattle, Washington. The new facility will house IonQ's growing R&D and manufacturing teams, as they develop systems to meet continued customer demand. With public support from U.S. Senator Patty Murray (D-WA) - an early proponent of the CHIPS and Science Act - and Congresswoman Suzan DelBene, US representative from Washington's 1st congressional district,today's announcement is part of IonQ's broader intent to invest $1 billion through expansion in the Pacific Northwest over the next 10 years.

"IonQ making the decision to open the first ever quantum computing manufacturing facility in the country right here in Bothell is a very big deal—and it's great news for Washington state," said Senator Murray. "Opening this facility will absolutely help ensure Washington state continues to be a leader in innovation and cutting-edge technologies—but it also means jobs that will be an investment in our families and their futures. These are the kinds of investments that happen when we pass legislation like the CHIPS and Science Act to invest in American manufacturing and build the economy of the future right here at home."

Today, Intel unveiled research breakthroughs fueling its innovation pipeline for keeping Moore's Law on track to a trillion transistors on a package in the next decade. At IEEE International Electron Devices Meeting (IEDM) 2022, Intel researchers showcased advancements in 3D packaging technology with a new 10x improvement in density; novel materials for 2D transistor scaling beyond RibbonFET, including super-thin material just 3 atoms thick; new possibilities in energy efficiency and memory for higher-performing computing; and advancements for quantum computing.

"Seventy-five years since the invention of the transistor, innovation driving Moore's Law continues to address the world's exponentially increasing demand for computing. At IEDM 2022, Intel is showcasing both the forward-thinking and concrete research advancements needed to break through current and future barriers, deliver to this insatiable demand, and keep Moore's Law alive and well for years to come." -Gary Patton, Intel vice president and general manager of Components Research and Design Enablement

IBM is one of the frontiers for using the natural properties of quantum particles to process the information on an enterprise scale. With constant advances in quantum information processing, the company is using newly found discoveries to double the size of its quantum processors. Using quantum properties instead of the conventional on/off switching of bits in the regular processors, quantum processors can process the information on a much larger scale. Last year, IBM unveiled the Eagle quantum processor with 127 qubits. This year, the company is bringing in 433 qubits to the table to power the next generation of enterprise and data center infrastructure.

Called IBM Osprey, it features IBM's 433 qubits cooled to cryogenic temperatures and in a controlled environment. While the computational power of the processor seems to be rather impressive, it is still a noisy quantum implementation that is sensitive to outside noise and requires exceptionally low temperatures to operate, such as -273 Degrees Celcius. To combat some of those obstacles, Osprey adds multi-level wiring to provide flexibility for signal routing and device layout while also adding integrated filtering to reduce noise and improve stability. Concurrently, IBM developed new signal delivery wiring that is 70% cheaper and produces the same result, driving up the ability to commercialize this design. For performance, IBM managed to increase quantum volume four times from 128 to 512 and a 10x improvement in Driving quantum performance from 1.4k to 15k Circuit Layer Operations Per Second (CLOPS).

The Intel Labs and Components Research organizations have demonstrated the industry's highest reported yield and uniformity to date of silicon spin qubit devices developed at Intel's transistor research and development facility, Gordon Moore Park at Ronler Acres in Hillsboro, Oregon. This achievement represents a major milestone for scaling and working towards fabricating quantum chips on Intel's transistor manufacturing processes.

The research was conducted using Intel's second-generation silicon spin test chip. Through testing the devices using the Intel cryoprober, a quantum dot testing device that operates at cryogenic temperatures (1.7 Kelvin or -271.45 degrees Celsius), the team isolated 12 quantum dots and four sensors. This result represents the industry's largest silicon electron spin device with a single electron in each location across an entire 300 millimeter silicon wafer.

Researchers at Toshiba Corporation have achieved a breakthrough in quantum computer architecture: the basic design for a double-transmon coupler that will improve the speed and accuracy of quantum computation in tunable couplers. The coupler is a key device in determining the performance of superconducting quantum computers.

Tunable couplers in a superconducting quantum computer link two qubits and perform quantum computations by turning on and off the coupling between them. Current technology can turn off the coupling of transmon qubits with close frequencies, but this is prone to crosstalk errors that occur on one of the qubits when the other qubit is irradiated with electromagnetic waves for control. In addition, current technology cannot completely turn off coupling for qubits with significantly different frequencies, resulting in errors due to residual coupling.

Baidu, Inc., a leading AI company with strong Internet foundation, today announced its first superconducting quantum computer that fully integrates hardware, software, and applications. On top of this, Baidu also introduced the world's first all-platform quantum hardware-software integration solution that provides access to various quantum chips via mobile app, PC, and cloud. Launched at Quantum Create 2022, a quantum developer conference held in Beijing, this new offering paves the way for the long-awaited industrialization of quantum computing.

A revolutionary technology that harnesses the laws of quantum mechanics to solve problems beyond the reach of classical computers, quantum computing is expected to bring ground-breaking transformations in fields like artificial intelligence (AI), computational biology, material simulation, and financial technology. However, a significant gap remains between quantum devices and services.

IonQ, an industry leader in quantum computing, announced IonQ Forte, its latest generation of quantum systems. The system features novel, cutting-edge optics technology that enables increased accuracy and further enhances IonQ's industry leading system performance. Forte is expected to be initially available for select developers, partners, and researchers in 2022 and is expected to be available for broader customer access in 2023. Forte is the latest evolution towards a "software-configurable quantum computer," which is designed to allow the company to optimize the computing hardware for targeted user problems-ultimately, giving users customized algorithmic performance. The new system features acousto-optic deflector (AOD) technology, which allows IonQ to dynamically direct laser beams that drive quantum gates towards individual ions. The AOD is designed to minimize noise and overcome variations in ion position, improving fidelity in long chains of trapped ions, which is crucial for scaling quantum computers. In addition, key parameters, including qubit and gate configuration, can be tailored to user needs, creating a truly dynamic and flexible system.

Forte joins IonQ Aria as the company's second system with capacity of up to 32 qubits, has AOD systems capable of addressing up to 40 individual ion qubits, and is currently configured to use 31 of them. With this technological leap, IonQ furthers its commitment to building ever more powerful quantum computers with an increasing number of algorithmic qubits, an application-oriented performance metric for quantum computers. The new announcement follows IonQ's announcement of open-source access to native gates, which allows quantum application developers to explore software breakthroughs on top of IonQ hardware without having to choose from a set menu of gates.

IBM today announced its new 127-quantum bit (qubit) 'Eagle' processor at the IBM Quantum Summit 2021, its annual event to showcase milestones in quantum hardware, software, and the growth of the quantum ecosystem. The 'Eagle' processor is a breakthrough in tapping into the massive computing potential of devices based on quantum physics. It heralds the point in hardware development where quantum circuits cannot be reliably simulated exactly on a classical computer. IBM also previewed plans for IBM Quantum System Two, the next generation of quantum systems.

Quantum computing taps into the fundamental quantum nature of matter at subatomic levels to offer the possibility of vastly increased computing power. The fundamental computational unit of quantum computing is the quantum circuit, an arrangement of qubits into quantum gates and measurements. The more qubits a quantum processor possesses, the more complex and valuable the quantum circuits that it can run.

Today, Intel and QuTech—a collaboration between Delft University of Technology and the Netherlands Organisation for Applied Scientific Research - published key findings in quantum research to address the "interconnect bottleneck" that exists between quantum chips that sit in cryogenic dilution refrigerators and the complex room-temperature electronics that control the qubits. The innovations were covered in Nature, the industry-leading science journal of peer-reviewed research, and mark an important milestone in addressing one of the biggest challenges to quantum scalability with Intel's cryogenic controller chip Horse Ridge.

"Our research results, driven in partnership with QuTech, quantitatively prove that our cryogenic controller, Horse Ridge, can achieve the same high-fidelity results as room-temperature electronics while controlling multiple silicon qubits. We also successfully demonstrated frequency multiplexing on two qubits using a single cable, which clears the way for simplifying the "wiring challenge" in quantum computing. Together, these innovations pave the way for fully integrating quantum control chips with the quantum processor in the future, lifting a major roadblock in quantum scaling," said Stefano Pellerano, principal engineer at Intel Labs.

PsiQuantum, the leading quantum computing company focused on delivering a 1 million-plus qubit quantum computer, and GLOBALFOUNDRIES (GF ), the global leader in feature-rich semiconductor manufacturing, today announced a major breakthrough in their partnership to build the world's first full-scale commercial quantum computer. The two companies are now manufacturing the silicon photonic and electronic chips that form the foundation of the Q1 system, the first system milestone in PsiQuantum's roadmap to deliver a commercially viable quantum computer with one million qubits (the basic unit of quantum information) and beyond.

PsiQuantum and GF have now demonstrated a world-first ability to manufacture core quantum components, such as single-photon sources and single-photon detectors, with precision and in volume, using the standard manufacturing processes of GF's world-leading semiconductor fab. The companies have also installed proprietary production and manufacturing equipment in two of GF's 300 mm fabs to produce thousands of Q1 silicon photonic chips at its facility in upstate New York, and state-of-the-art electronic control chips at its Fab 1 facility in Dresden, Germany.

At an Intel Labs virtual event today, Intel unveiled Horse Ridge II, its second-generation cryogenic control chip, marking another milestone in the company's progress toward overcoming scalability, one of quantum computing's biggest hurdles. Building on innovations in the first-generation Horse Ridge controller introduced in 2019, Horse Ridge II supports enhanced capabilities and higher levels of integration for elegant control of the quantum system. New features include the ability to manipulate and read qubit states and control the potential of several gates required to entangle multiple qubits.

"With Horse Ridge II, Intel continues to lead innovation in the field of quantum cryogenic controls, drawing from our deep interdisciplinary expertise bench across the Integrated Circuit design, Labs and Technology Development teams. We believe that increasing the number of qubits without addressing the resulting wiring complexities is akin to owning a sports car, but constantly being stuck in traffic. Horse Ridge II further streamlines quantum circuit controls, and we expect this progress to deliver increased fidelity and decreased power output, bringing us one step closer toward the development of a 'traffic-free' integrated quantum circuit."-Jim Clarke, Intel director of Quantum Hardware, Components Research Group, Intel.

Honeywell, a multinational conglomerate specializing in the quantum computing field, today announced they have created the world's most advanced quantum computer. Their new solution brings about a quantum computing volume set at 64 - twice the quantum volume of the world's previous most powerful quantum computer, the IBM Raleigh. You might be looking at that 64 quantum volume, wondering what that means - and where did the qubits metric go. Well, the thing with quantum computers is that the number of qubits can't really be looked at as a definite measure of performance - instead, it's just a part of the "quantum volume" calculation, which expresses the final performance of a quantum system.

When you make operations at the quantum level, a myriad of factors come into play that adversely impact performance besides the absolute number of qubits, such as the calculation error rate (ie, how often the system outputs an erroneous answer to a given problem) as well as the qubit connectivity level. Qubit connectivity expresses a relationship between the quantum hardware capabilities of a given machine and the ability of the system to distribute workloads across qubits - sometimes the workloads can only be distributed to two adjacent qubits, other times, it can be distributed to qubits that are more far apart within the system without losing data coherency and without affecting error rates - thus increasing performance and the systems' flexibility towards processing workloads. If you've seen Alex Garland's Devs series on Hulu (and you should; it's great), you can see a would-be-quantum computer and all its intricate connections. Quantum computers really are magnificent crossovers of science, materials engineering, and computing. Of course, the quantum computing arms race means that Honeywell's system will likely be dethroned by quantum volume rather soon.

Intel, in collaboration with QuTech, today published a paper in Nature demonstrating the successful control of "hot" qubits, the fundamental unit of quantum computing, at temperatures greater than 1 kelvin. The research also highlighted individual coherent control of two qubits with single-qubit fidelities of up to 99.3%. These breakthroughs highlight the potential for cryogenic controls of a future quantum system and silicon spin qubits, which closely resemble a single electron transistor, to come together in an integrated package.

"This research represents a meaningful advancement in our research into silicon spin qubits, which we believe are promising candidates for powering commercial-scale quantum systems, given their resemblance to transistors that Intel has been manufacturing for more than 50 years. Our demonstration of hot qubits that can operate at higher temperatures while maintaining high fidelity paves the way to allow a variety of local qubit control options without impacting qubit performance," said Jim Clarke, director of quantum hardware, Intel Labs.

Intel Labs, in collaboration with QuTech ‑ a partnership between TU Delft and TNO (Netherlands Organization for Applied Scientific Research) ‑ outlines key technical features of its new cryogenic quantum control chip "Horse Ridge" in a research paper released at the 2020 International Solid-State Circuits Conference (ISSCC) in San Francisco. The paper unveils key technical capabilities of Horse Ridge that address fundamental challenges in building a quantum system powerful enough to demonstrate quantum practicality: scalability, flexibility and fidelity.

"Today, quantum researchers work with just a small number of qubits, using smaller, custom-designed systems surrounded by complex control and interconnect mechanisms. Intel's Horse Ridge greatly minimizes this complexity. By systematically working to scale to thousands of qubits required for quantum practicality, we're continuing to make steady progress toward making commercially viable quantum computing a reality in our future," said Jim Clarke, director of quantum hardware, Intel Labs.

Intel researchers are taking new steps toward quantum computers by testing a tiny new "spin qubit" chip. The new chip was created in Intel's D1D Fab in Oregon using the same silicon manufacturing techniques that the company has perfected for creating billions of traditional computer chips. Smaller than a pencil's eraser, it is the tiniest quantum computing chip Intel has made.

The new spin qubit chip runs at the extremely low temperatures required for quantum computing: roughly 460 degrees below zero Fahrenheit - 250 times colder than space. The spin qubit chip does not contain transistors - the on/off switches that form the basis of today's computing devices - but qubits (short for "quantum bits") that can hold a single electron. The behavior of that single electron, which can be in multiple spin states simultaneously, offers vastly greater computing power than today's transistors, and is the basis of quantum computing.

(Editor's Note: Quantum supremacy may still be some years away as researchers strive to surpass the challenges of keeping such exotic systems stable and error-free enough for them to provide actually useful in more complex calculations. As complexity increases, so does the system's stability decrease, so researchers have to come up with novel ways of not only expanding the scope of the quantum computer, but also stabilizing it. That quantum supremacy is some years away should elicit a sigh of relief from users, as it means that our current encryption techniques will be relevant for that much more time; however, it's really only a matter of time before quantum-based encryption schemes are necessary to maintain the status quo. Of course, general purpose computers will - and do - keep on evolving and increasing in performance as well, so quantum supremacy may find itself chasing the goose, so to speak, for a little more time.)

The goal of the Google Quantum AI lab is to build a quantum computer that can be used to solve real-world problems. Our strategy is to explore near-term applications using systems that are forward compatible to a large-scale universal error-corrected quantum computer. In order for a quantum processor to be able to run algorithms beyond the scope of classical simulations, it requires not only a large number of qubits. Crucially, the processor must also have low error rates on readout and logical operations, such as single and two-qubit gates.

Japan's Nippon Telegraph and Telephone Company (NTT) is opening up its prototype quantum computing system for public use over the internet, giving users around the world access to one of the most elusive pieces of tech that this world has yet seem. Maybe we haven't seen it, though; observation does change the outcome, and these quantum physics really are as finicky as they come. Starting Nov. 27, Japan joins China and the U.S. in the race to develop the world's most advanced computers - and Japan has chosen the free, quantum-democratizing approach.

The NTT quantum computing solution is a state-sponsored research project, developed in conjunction with the National Institute of Informatics, Osaka university, and other partners. It has taken a different technical approach from other quantum computing developers, in that this particular computing system is exploiting the properties of light. Widely (un)known as Linear Optics Quantum Computation (LOQC), this particular approach foregoes qubits (which are extremely difficult to keep from decohering, and usually require very exotic cooling techniques to increase the qubits' stability. LOQC abandons qubits and uses photons to represent them as information carriers through linear optical elements (such as beam splitters, phase shifters, and mirrors). This allows the machine to process quantum information, using photon detectors and quantum memories to detect and store quantum information.